Allow dex jars from prebuilt_apex to be used by hiddenapi

Invokes hiddenAPIExtractInformation() on the dex jar provided by the
deapexer (on behalf of prebuilt_apex) so that hiddenAPI can extract the
information it needs, if anything, from the dex file (and accompanying
classes implementation file).

The dex file provided by deapexer has already had the hiddenapi
information encoded into it so it does not need to do that again.

This change adds the primary parameter to hiddenAPIExtractInformation()
and checks it (and also the hiddenAPI.active property) before it does
anything. That ensures that it behaves correctly when called directly
as well as when called from hiddenAPIExtractAndEncode().

Bug: 178361284
Test: m droid
      Verified that hiddenapi files (both aggregated ones and for the
      individual modules) are not affected by this change.
      Also verified that the hiddenapi files created when using the
      prebuilts (using SOONG_CONFIG_art_module_source_build=false) are
      the same as when using the source. There is a slight difference
      in the order but otherwise identical.
Change-Id: I7abb63fd310bb94787ab7f4821e5fd283dc03046
diff --git a/java/hiddenapi.go b/java/hiddenapi.go
index 66d9ca0..069595e 100644
--- a/java/hiddenapi.go
+++ b/java/hiddenapi.go
@@ -144,12 +144,7 @@
 		return dexJar
 	}
 
-	// More than one library with the same classes may need to be encoded but only one should be
-	// used as a source of information for hidden API processing otherwise it will result in
-	// duplicate entries in the files.
-	if primary {
-		h.hiddenAPIExtractInformation(ctx, dexJar, implementationJar)
-	}
+	h.hiddenAPIExtractInformation(ctx, dexJar, implementationJar, primary)
 
 	if !h.annotationsOnly {
 		hiddenAPIJar := android.PathForModuleOut(ctx, "hiddenapi", name+".jar").OutputPath
@@ -169,7 +164,18 @@
 //
 // It also makes the dex jar available for use when generating the
 // hiddenAPISingletonPathsStruct.stubFlags.
-func (h *hiddenAPI) hiddenAPIExtractInformation(ctx android.ModuleContext, dexJar, classesJar android.Path) {
+func (h *hiddenAPI) hiddenAPIExtractInformation(ctx android.ModuleContext, dexJar, classesJar android.Path, primary bool) {
+	if !h.active {
+		return
+	}
+
+	// More than one library with the same classes may need to be encoded but only one should be
+	// used as a source of information for hidden API processing otherwise it will result in
+	// duplicate entries in the files.
+	if !primary {
+		return
+	}
+
 	stubFlagsCSV := hiddenAPISingletonPaths(ctx).stubFlags
 
 	flagsCSV := android.PathForModuleOut(ctx, "hiddenapi", "flags.csv")