Create a CI workflow to build common component protos. (#121)

Author: rofrankel

.github/workflows/build-protos.yaml

@@ -0,0 +1,16 @@
+---
+name: build-protos
+on:
+  pull_request:
+    paths:
+      - 'common-components/proto/**/*.proto'
+jobs:
+  build-protos:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: bufbuild/buf-setup-action@v1.19.0
+
+      - name: Verify proper formatting.
+        run: buf build common-components/proto