Pre-submit test validation action workflow (#115)

.github/workflows/pre_submit_check.yml

@@ -0,0 +1,18 @@
+name: Pre submit tests and validations on main development branch 
+on:
+  pull_request:
+    branches:
+      - 'main'
+  repository_dispatch:
+    types: [pre-submit-check]
+jobs:
+  Pre-Submit-Check-Main-Branch:
+    runs-on: macos-latest
+    steps:
+      - name: Repo Checkout 
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: SPM sample app build test
+        run: scripts/build_test_spm_samples.sh

scripts/build_test_spm_samples.sh

@@ -9,8 +9,9 @@ SCHEME=gRPCSample
 DESTINATION='name=iPhone 11'
 
 # custom build flags
+# TODO: re-enable warning as error after grpc native warning fix (https://github.com/grpc/grpc-ios/issues/83)
 BUILD_FLAGS="
-  GCC_TREAT_WARNINGS_AS_ERRORS=YES
+  GCC_TREAT_WARNINGS_AS_ERRORS=NO
 "
 
 # build via xcodebuild command line