Fixing protoOutParams concatenation.

ParseGeneratorParameter delimits based on commas, not colons:
external/protobuf/src/google/protobuf/compiler/code_generator.cc

Bug: 72570104
Test: flash device with new build
Change-Id: I00042782a718d288ca6b0cb78f856d0fb223a926
(cherry picked from commit fb5b31ce9675e1acbba2d6eb0c0739195515fb85)
diff --git a/cc/util.go b/cc/util.go
index aaf0f71..1e4a0c0 100644
--- a/cc/util.go
+++ b/cc/util.go
@@ -67,7 +67,7 @@
 		cppFlags:       strings.Join(in.CppFlags, " "),
 		yaccFlags:      strings.Join(in.YaccFlags, " "),
 		protoFlags:     strings.Join(in.protoFlags, " "),
-		protoOutParams: strings.Join(in.protoOutParams, ":"),
+		protoOutParams: strings.Join(in.protoOutParams, ","),
 		aidlFlags:      strings.Join(in.aidlFlags, " "),
 		rsFlags:        strings.Join(in.rsFlags, " "),
 		ldFlags:        strings.Join(in.LdFlags, " "),