core: Dynamically inject Tensor features for Play Store compatibility

Inject Tensor-specific features dynamically via getSystemAvailableFeatures()
to ensure Play Store and other services recognize them as system-declared
features instead of relying solely on hasSystemFeature() overrides.

This improves compatibility with Tensor-targeted GApps and allows updates
to appear correctly in Play Store.

Also expose invalidateHasSystemFeatureCache() to allow cache refresh when
spoofing state changes.

- Inject FEATURES_TENSOR into system feature list when enabled
- Keep hasSystemFeature() override for runtime checks
- Add cache invalidation support for immediate effect

Note:
Play Store may still require a reboot or process restart due to
server-side and process-level caching.

Author: joeyhuab

core/java/android/app/ApplicationPackageManager.java

@@ -792,12 +792,32 @@ public FeatureInfo[] getSystemAvailableFeatures() {
             if (parceledList == null) {
                 return new FeatureInfo[0];
             }
-            final List<FeatureInfo> list = parceledList.getList();
-            final FeatureInfo[] res = new FeatureInfo[list.size()];
-            for (int i = 0; i < res.length; i++) {
-                res[i] = list.get(i);
+            final List<FeatureInfo> list = new ArrayList<>(parceledList.getList());
+
+            // Inject Tensor features when toggle is enabled
+            final boolean forceTensor = SystemProperties.getBoolean(
+                    "persist.sys.pp.tensor", false);
+
+            if (forceTensor && !IS_TENSOR_DEVICE) {
+                for (String feature : FEATURES_TENSOR) {
+                    boolean exists = false;
+
+                    for (FeatureInfo fi : list) {
+                        if (feature.equals(fi.name)) {
+                            exists = true;
+                            break;
+                        }
+                    }
+
+                    if (!exists) {
+                        FeatureInfo fi = new FeatureInfo();
+                        fi.name = feature;
+                        fi.version = 0;
+                        list.add(fi);
+                    }
+                }
             }
-            return res;
+            return list.toArray(new FeatureInfo[0]);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }