Surface Java APIs Used By APK-only Modules.

Previously we were only generating used-by API-coverage for APEX modules.
This change adds support for APK-only modules such as NetworkStack and DocumentsUI.

Bug: b/216313756
Forrest Run: https://android-build.googleplex.com/builds/abtd/run/L10800000953846781

Test: TARGET_BUILD_VARIANT=userdebug PRODUCT=mainline_modules_x86 ./vendor/google/build/build_unbundled_coverage_mainline_module.sh -j16

Change-Id: Id17e4a55c2a52e9903632a654e778f8d54982dfc
Merged-In: Id17e4a55c2a52e9903632a654e778f8d54982dfc
(cherry picked from commit 56d75785bd)

java/app.go

@@ -169,6 +169,8 @@ type AndroidApp struct {
 	overriddenManifestPackageName string
 
 	android.ApexBundleDepsInfo
+
+	javaApiUsedByOutputFile android.ModuleOutPath
 }
 
 func (a *AndroidApp) IsInstallable() bool {
@@ -277,6 +279,7 @@ func (a *AndroidTestHelperApp) GenerateAndroidBuildActions(ctx android.ModuleCon
 func (a *AndroidApp) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.checkAppSdkVersions(ctx)
 	a.generateAndroidBuildActions(ctx)
+	a.generateJavaUsedByApex(ctx)
 }
 
 func (a *AndroidApp) checkAppSdkVersions(ctx android.ModuleContext) {