chore: install protocol buffer before building service (#3599)

## Purpose of this PR

The most recent service update added a dependency to the protocol buffer
compiler. This PR adds the protocol buffer driver to the CI DA service
build script.

### Jira ticket
NA

<!-- Uncomment and mark items off with a * if this PR deprecates any
API:
### Deprecated API
- [ ] An `[Obsolete]` attribute was added along with a `(RemovedAfter
yyyy-mm-dd)` entry.
- [ ] An [api
updater](https://confluence.unity3d.com/display/DEV/Obsolete+API+updaters)
was added.
- [ ] Deprecation of the API is explained in the CHANGELOG.
- [ ] The users can understand why this API was removed and what they
should use instead.
-->

## Documentation

- No documentation changes or additions were necessary.

## Testing & QA
[//]: #  (
This section is REQUIRED and should describe how the changes were tested
and how should they be tested when Playtesting for the release.
It can range from "edge case covered by unit tests" to "manual testing
required and new sample was added".
Expectation is that PR creator does some manual testing and provides a
summary of it here.)

### Functional Testing
[//]: # (If checked, List manual tests that have been performed.)
_Manual testing :_
- [X] `Manual testing done`
  - Via back-end CI.

_Automated tests:_
- [ ] `Covered by existing automated tests`
- [ ] `Covered by new automated tests`

_Does the change require QA team to:_

- [ ] `Review automated tests`?
- [ ] `Execute manual tests`?

If any boxes above are checked, please add QA as a PR reviewer.

## Backport
No back port is required (a v2.x.x only update)

Author: NoelStephensUnity

Tools/CI/run_cmb_service.sh

@@ -60,33 +60,98 @@ echo "Starting with echo server on port: $echo_port and the cmb service on port:
 
 # Setup -------------------------------------------------------------------------
 
+
+ThrewError=false
+
+# Mimics "Try-Catch" where you have to check if an error occurred after invoking
+try() {
+   ThrewError=false
+  "$@" || throw "$@"
+}
+
+# Invoked by try
+throw() {
+    logError "An error occurred executing this command:$@"
+    ThrewError=true
+}
+
+# A way to log messages that are easy to distinguish from the rest of the logs
+logMessage(){
+    printf "\n############################################\n"
+    printf "$@\n"
+    printf "############################################\n"
+}
+
+# A way to log error messages that are easy to distinguish from the rest of the logs
+logError(){
+    printf "\n!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n"
+    printf "$@\n"
+    printf "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n"
+}
+
+# Protocol Buffer Compiler ------------------------------------------------------
+
+# Apply any updates 
+logMessage "Updating modules..."
+sudo apt-get update
+
+# Install Protocol Buffer Compiler (using apt-get)
+logMessage "Installing protocol bufffer compiler as SUDO..."
+try sudo apt-get install -y protobuf-compiler
+
+# If the previous command failed, try without sudo
+if $ThrewError; then
+logMessage "Installing protocol bufffer compiler as shell assigned account..."
+apt-get install -y protobuf-compiler
+else
+logMessage "Protocol bufffer compiler was installed as sudo!"
+fi
+
+# Add the PROTOC environment variable that points to the Protocol Buffer Compiler binary
+export PROTOC="/usr/bin/protoc"
+
+# Validate the PROTOC env var by getting the protoc version
+try $PROTOC --version
+
+if $ThrewError; then
+logError "Failed to properly run protoc!"
+exit -1
+else
+logMessage "Protocol Buffer Compiler Installed & ENV variables verified!\n PROTOC path is: $PROTOC"
+fi
+
 # clone the cmb service repo
 git clone https://github.com/Unity-Technologies/mps-common-multiplayer-backend.git
+
 # navigate to the cmb service directory
 cd ./mps-common-multiplayer-backend/runtime
 
 # Install rust
 curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+
 # Add the cargo bin directory to the PATH
 export PATH="$HOME/.cargo/bin:$PATH"
 
-
 # Echo server -------------------------------------------------------------------
 
 # Build the echo server
+logMessage "Beginning echo server build..."
 cargo build --example ngo_echo_server
+
 # Run the echo server in the background
+logMessage "Running echo server tests..."
 cargo run --example ngo_echo_server -- --port $echo_port &
 
-
 # CMB Service -------------------------------------------------------------------
 
 # Build a release version of the standalone cmb service
+logMessage "Beginning service release build..."
 cargo build --release --locked
 
 # Run the standalone service on an infinite loop in the background.
 # The infinite loop is required as the service will exit each time all connected clients disconnect.
 # This means the service will exit after each test. The infinite loop will immediately restart the service each time it exits.
+logMessage "Running service integration tests..."
 while :; do
   ./target/release/comb-server -l error --metrics-port 5000 standalone --port $service_port -t 60m;
 done & # <- use & to run the entire loop in the background