Don't build hiddenapi flags or encode dex for unbundled builds

Builds with TARGET_BUILD_APPS shouldn't build the hiddenapi flags
or encode dex files even if frameworks/base exists.

Bug: 133343287
Test: mainline modules build
Change-Id: I0647451420fd09bb680808b35e1ad3b8f514ba46
Merged-In: I0647451420fd09bb680808b35e1ad3b8f514ba46
(cherry picked from commit 9c74a1ee85)

java/hiddenapi_singleton.go

@@ -61,7 +61,7 @@ func (h *hiddenAPISingleton) GenerateBuildActions(ctx android.SingletonContext)
 	stubFlagsRule(ctx)
 
 	// These rules depend on files located in frameworks/base, skip them if running in a tree that doesn't have them.
-	if ctx.Config().FrameworksBaseDirExists(ctx) {
+	if ctx.Config().FrameworksBaseDirExists(ctx) && !ctx.Config().UnbundledBuild() {
 		h.flags = flagsRule(ctx)
 		h.metadata = metadataRule(ctx)
 	} else {