Allow using reserved package IDs

Pre-O, the platform treats negative resource IDs [those with
a package ID of 0x80 or higher] as invalid.  In order to work
around this limitation, we allow the use of traditionally
reserved resource IDs [those between 0x02 and 0x7E].

Bug: 78041707
Test: ./out/host/linux-x86/nativetest64/aapt2_tests/aapt2_tests
Test: ./out/host/linux-x86/nativetest/libandroidfw_tests/libandroidfw_tests
Test: Manual. Create a feature split with a package ID of 0x7E and see it runs and can reference base resources.

Change-Id: I3d9782cc05d3a55e1a2467bf39566788847e1160
diff --git a/tools/aapt2/ResourceValues.cpp b/tools/aapt2/ResourceValues.cpp
index 6f213e1..34b46c5 100644
--- a/tools/aapt2/ResourceValues.cpp
+++ b/tools/aapt2/ResourceValues.cpp
@@ -117,8 +117,7 @@
 
 bool Reference::Flatten(android::Res_value* out_value) const {
   const ResourceId resid = id.value_or_default(ResourceId(0));
-  const bool dynamic = resid.is_valid_dynamic() && resid.package_id() != kFrameworkPackageId &&
-                       resid.package_id() < kAppPackageId;
+  const bool dynamic = resid.is_valid_dynamic() && is_dynamic;
 
   if (reference_type == Reference::Type::kResource) {
     if (dynamic) {