Add a kokoro boot test that substitutes bin/assemble_cvd and bin/run_cvd

We have been migrating executables to the GitHub source tree. Using the
`debian_substitution_marker` field driven by the Android build, the
device build can request certain executables are substituted with the
latest version built from this source tree rather than use the one
shipped with the device build.

Some executables with migrated source have never been rolled out to
production, and had no end-to-end test coverage. This has allowed broken
versions of these executables to be included in releases, delaying the
substitution and use of those executables.

Adding the capability and execution of new tests on executables that are
not yet rolled out will improve our chances at rolling out these
executables later.

Bug: b/461909300

Author: Databean

e2etests/cvd/BUILD.bazel

@@ -58,6 +58,26 @@ cvd_command_boot_test(
     target = "aosp_cf_x86_64_only_phone-userdebug",
 )
 
+cvd_command_boot_test(
+    name = "aosp_additional_substitution",
+    branch = "aosp-android-latest-release",
+    target = "aosp_cf_x86_64_only_phone-userdebug",
+    substitutions = [
+        "bin/assemble_cvd",
+        "bin/run_cvd",
+    ],
+)
+
+cvd_command_boot_test(
+    name = "git_main_additional_substitution",
+    branch = "git_main",
+    target = "aosp_cf_x86_64_only_phone-trunk_staging-userdebug",
+    substitutions = [
+        "bin/assemble_cvd",
+        "bin/run_cvd",
+    ],
+)
+
 cvd_command_boot_test(
     name = "take_bugreport",
     branch = "aosp-android-latest-release",

e2etests/cvd/boot_tests.bzl

@@ -31,10 +31,12 @@ def cvd_load_boot_test(name, env_file, size = "medium", credential_source = ""):
         ],
     )
 
-def cvd_command_boot_test(name, branch, target, cvd_command, credential_source = ""):
+def cvd_command_boot_test(name, branch, target, cvd_command = [], credential_source = "", substitutions = ""):
     args = ["-b", branch, "-t", target]
     if credential_source:
         args += ["-c", credential_source]
+    if substitutions:
+        args += ["-s", ",".join(substitutions)]
     args += cvd_command
     native.sh_test(
         name = name,

e2etests/cvd/cvd_command_boot_test.sh

@@ -6,14 +6,17 @@ BRANCH=""
 TARGET=""
 CREDENTIAL_SOURCE="${CREDENTIAL_SOURCE:-}"
 
-while getopts "c:b:t:" opt; do
+while getopts "b:c:s:t:" opt; do
   case "${opt}" in
     b)
       BRANCH="${OPTARG}"
       ;;
     c)
       CREDENTIAL_SOURCE="${OPTARG}"
       ;;
+    s)
+      SUBSTITUTIONS="${OPTARG}"
+      ;;
     t)
       TARGET="${OPTARG}"
       ;;
@@ -59,14 +62,25 @@ credential_arg=""
 if [[ -n "$CREDENTIAL_SOURCE" ]]; then
     credential_arg="--credential_source=${CREDENTIAL_SOURCE}"
 fi
+
 cvd fetch \
   --default_build="${BRANCH}/${TARGET}" \
   --target_directory="${workdir}" \
   ${credential_arg}
 
+# This argument is supported at fetch and create time. Applying it to both
+# invocations would make it replace the debian_substition_marker list, applying
+# it only to one out of two cases makes it additive.
+substitution_arg=""
+if [[ -n "$SUBSTITUTIONS" ]]; then
+  substitution_arg="--host_substitutions=${SUBSTITUTIONS}"
+fi
+
 (
   cd "${workdir}"
-  cvd create --report_anonymous_usage_stats=y --undefok=report_anonymous_usage_stats
-  cvd "$@"
+  cvd create ${substitution_arg} --report_anonymous_usage_stats=y --undefok=report_anonymous_usage_stats
+  if (( $# > 0 )); then
+    cvd "$@"
+  fi
   cvd rm
 )