CI: Support set manager signature size and hash (#757)

close #739, close #745, close #752

.github/workflows/gki-kernel.yml

@@ -144,7 +144,12 @@ jobs:
 
       - name: Build boot.img
         working-directory: android-kernel
-        run: CCACHE="/usr/bin/ccache" LTO=thin BUILD_CONFIG=common/build.config.gki.aarch64 build/build.sh
+        run: |
+          if [ ! -z ${{ vars.EXPECTED_SIZE }} ] && [ ! -z ${{ vars.EXPECTED_HASH }} ]; then
+            export KSU_EXPECTED_SIZE=${{ vars.EXPECTED_SIZE }}
+            export KSU_EXPECTED_HASH=${{ vars.EXPECTED_HASH }}
+          fi
+          CCACHE="/usr/bin/ccache" LTO=thin BUILD_CONFIG=common/build.config.gki.aarch64 build/build.sh
 
       - name: Prepare artifacts
         id: prepareArtifacts