Add setting/experiment for small battery devices to have
all forced app standby enabled except for when the device
is charging.

Reverting the revert of this CL. The only change is to use
EXTRA_PLUGGED instead of EXTRA_STATUS in detecting charging
state. Verified that this passes CTS test for battery saver.

Bug: 69259147
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/ForceAppStandbyTrackerTest.java
Test: atest CtsBatterySavingTestCases
Change-Id: I4f3ffc0c865a1a3a035b6d9d6838b5056b666eb9
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 8c2a8ae..c9e8621 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -9896,6 +9896,15 @@
         public static final String FORCED_APP_STANDBY_ENABLED = "forced_app_standby_enabled";
 
         /**
+         * Whether or not to enable Forced App Standby on small battery devices.
+         * Type: int (0 for false, 1 for true)
+         * Default: 0
+         * @hide
+         */
+        public static final String FORCED_APP_STANDBY_FOR_SMALL_BATTERY_ENABLED
+                = "forced_app_standby_for_small_battery_enabled";
+
+        /**
          * Whether or not Network Watchlist feature is enabled.
          * Type: int (0 for false, 1 for true)
          * Default: 0
diff --git a/core/proto/android/server/forceappstandbytracker.proto b/core/proto/android/server/forceappstandbytracker.proto
index 8753bf7..c9f7d52 100644
--- a/core/proto/android/server/forceappstandbytracker.proto
+++ b/core/proto/android/server/forceappstandbytracker.proto
@@ -41,4 +41,13 @@
 
   // Packages that are disallowed OP_RUN_ANY_IN_BACKGROUND.
   repeated RunAnyInBackgroundRestrictedPackages run_any_in_background_restricted_packages = 5;
+
+  // Whether device is a small battery device
+  optional bool is_small_battery_device = 6;
+
+  // Whether force app standby for small battery device setting is enabled
+  optional bool force_all_apps_standby_for_small_battery = 7;
+
+  // Whether device is charging
+  optional bool is_charging = 8;
 }
diff --git a/core/tests/coretests/src/android/provider/SettingsBackupTest.java b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
index 37b3180..1482baf 100644
--- a/core/tests/coretests/src/android/provider/SettingsBackupTest.java
+++ b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
@@ -213,6 +213,7 @@
                     Settings.Global.FANCY_IME_ANIMATIONS,
                     Settings.Global.FORCE_ALLOW_ON_EXTERNAL,
                     Settings.Global.FORCED_APP_STANDBY_ENABLED,
+                    Settings.Global.FORCED_APP_STANDBY_FOR_SMALL_BATTERY_ENABLED,
                     Settings.Global.FSTRIM_MANDATORY_INTERVAL,
                     Settings.Global.GLOBAL_HTTP_PROXY_EXCLUSION_LIST,
                     Settings.Global.GLOBAL_HTTP_PROXY_HOST,