Update run_integration_tests.sh

Change the syntax for linux shell script.

Author: lahirumaramba

.github/scripts/run_integration_tests.sh

@@ -14,12 +14,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+set -e
+set -u
+
 mkdir -p FirebaseAdmin/FirebaseAdmin.IntegrationTests/resources
 
-gpg --quiet --batch --yes --decrypt --passphrase=$Env:FIREBASE_SERVICE_ACCT_KEY `
---output FirebaseAdmin/FirebaseAdmin.IntegrationTests/resources/integration_cert.json `
+gpg --quiet --batch --yes --decrypt --passphrase="${FIREBASE_SERVICE_ACCT_KEY}" \
+--output FirebaseAdmin/FirebaseAdmin.IntegrationTests/resources/integration_cert.json \
 .github/resources/integ-service-account.json.gpg
 
-echo $Env:FIREBASE_API_KEY > FirebaseAdmin/FirebaseAdmin.IntegrationTests/resources/integration_apikey.txt
+echo "${FIREBASE_API_KEY}" > FirebaseAdmin/FirebaseAdmin.IntegrationTests/resources/integration_apikey.txt
 
 dotnet test FirebaseAdmin/FirebaseAdmin.IntegrationTests