Fix wrong use if "!UserHandle.isApp()"

Turned out !UserHandle.isApp() doesn't mean "is system" because of isolated UIDs.

Bug: 72174012
Test: atest $ANDROID_BUILD_TOP/frameworks/base/services/tests/servicestests/src/com/android/server/ForceAppStandbyTrackerTest.java
Change-Id: Ibf6175d550ecc74677877c74db2473bf3f30132d

1 files changed, 22 insertions, 2 deletions

diff --git a/core/java/android/os/UserHandle.java b/core/java/android/os/UserHandle.java
index 6381b56a6503..5be72bc5c54b 100644
--- a/core/java/android/os/UserHandle.java
+++ b/core/java/android/os/UserHandle.java
@@ -126,7 +126,10 @@ public final class UserHandle implements Parcelable {
         return getAppId(uid1) == getAppId(uid2);
     }
 
-    /** @hide */
+    /**
+     * Whether a UID is an "isolated" UID.
+     * @hide
+     */
     public static boolean isIsolated(int uid) {
         if (uid > 0) {
             final int appId = getAppId(uid);
@@ -136,7 +139,11 @@ public final class UserHandle implements Parcelable {
         }
     }
 
-    /** @hide */
+    /**
+     * Whether a UID belongs to a regular app. *Note* "Not a regular app" does not mean
+     * "it's system", because of isolated UIDs. Use {@link #isCore} for that.
+     * @hide
+     */
     public static boolean isApp(int uid) {
         if (uid > 0) {
             final int appId = getAppId(uid);
@@ -147,6 +154,19 @@ public final class UserHandle implements Parcelable {
     }
 
     /**
+     * Whether a UID belongs to a system core component or not.
+     * @hide
+     */
+    public static boolean isCore(int uid) {
+        if (uid > 0) {
+            final int appId = getAppId(uid);
+            return appId < Process.FIRST_APPLICATION_UID;
+        } else {
+            return false;
+        }
+    }
+
+    /**
      * Returns the user for a given uid.
      * @param uid A uid for an application running in a particular user.
      * @return A {@link UserHandle} for that user.