Export proto deps from reused libraries too

The deps have to be exported alongside the headers to make sure
the headers are in place when a module that depends on the shared
library builds.

Bug: 37555583
Test: use protos in a cc_library
Change-Id: I8f5b8d7937868458c1cf02b990a348aa395634da
diff --git a/cc/cc.go b/cc/cc.go
index f368a13..dd73504 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -950,9 +950,10 @@
 
 		if tag == reuseObjTag {
 			if l, ok := cc.compiler.(libraryInterface); ok {
-				objs, flags := l.reuseObjs()
+				objs, flags, deps := l.reuseObjs()
 				depPaths.Objs = depPaths.Objs.Append(objs)
 				depPaths.ReexportedFlags = append(depPaths.ReexportedFlags, flags...)
+				depPaths.ReexportedFlagsDeps = append(depPaths.ReexportedFlagsDeps, deps...)
 				return
 			}
 		}