Stop ignoring classes on the classpath for stubs

We're working on moving the libcore classes away from srcs and into the
classpath, and ignoring classes on the classpath will cause incorrect
API signatures once that happens (several libcore classes appear in
public API signatures).

Keep the docs building in the same way they were before. They will be
addressed in separate CLs.

Bug: 173606718
Test: m checkapi
Change-Id: I471327c3657662d7a093e9baa2fb6e08d640f895
diff --git a/ApiDocs.bp b/ApiDocs.bp
index ba93a48..ada80bb 100644
--- a/ApiDocs.bp
+++ b/ApiDocs.bp
@@ -91,7 +91,9 @@
     arg_files: [
         "core/res/AndroidManifest.xml",
     ],
-    args: metalava_framework_docs_args,
+    args: metalava_framework_docs_args +
+        // Needed for hidden libcore annotations for now.
+        " --ignore-classes-on-classpath ",
     write_sdk_values: true,
 }
 
@@ -101,7 +103,10 @@
     arg_files: [
         "core/res/AndroidManifest.xml",
     ],
-    args: metalava_framework_docs_args + " --show-annotation android.annotation.SystemApi\\(client=android.annotation.SystemApi.Client.PRIVILEGED_APPS\\) ",
+    args: metalava_framework_docs_args +
+        // Needed for hidden libcore annotations for now.
+        " --ignore-classes-on-classpath " +
+        " --show-annotation android.annotation.SystemApi\\(client=android.annotation.SystemApi.Client.PRIVILEGED_APPS\\) ",
     write_sdk_values: true,
 }