Send broadcast to pkg installers on config change

Send a protected system broadcast to apps that hold
the INSTALL_PACKAGES permission whenever a change to
properties like locale or display density happens.

Receivers can be registered in the manifest, and a process
will be woken up to receive the broadcast.

This will happen rarely, since the configuration changes
eligible to trigger this broadcast are rare themselves.

Bug: 63918966
Test: manual

Change-Id: I817a51ea05f762e02561691825d57d643db7dc30
diff --git a/api/system-current.txt b/api/system-current.txt
index 6a6d667..3dbb333 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -829,6 +829,7 @@
     field public static final java.lang.String ACTION_RESOLVE_INSTANT_APP_PACKAGE = "android.intent.action.RESOLVE_INSTANT_APP_PACKAGE";
     field public static final java.lang.String ACTION_REVIEW_PERMISSIONS = "android.intent.action.REVIEW_PERMISSIONS";
     field public static final deprecated java.lang.String ACTION_SIM_STATE_CHANGED = "android.intent.action.SIM_STATE_CHANGED";
+    field public static final java.lang.String ACTION_SPLIT_CONFIGURATION_CHANGED = "android.intent.action.SPLIT_CONFIGURATION_CHANGED";
     field public static final java.lang.String ACTION_UPGRADE_SETUP = "android.intent.action.UPGRADE_SETUP";
     field public static final java.lang.String ACTION_USER_REMOVED = "android.intent.action.USER_REMOVED";
     field public static final java.lang.String ACTION_VOICE_ASSIST = "android.intent.action.VOICE_ASSIST";
diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index fa73e3c..12d4079 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -2399,6 +2399,26 @@
      */
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
     public static final String ACTION_CONFIGURATION_CHANGED = "android.intent.action.CONFIGURATION_CHANGED";
+
+    /**
+     * Broadcast Action: The current device {@link android.content.res.Configuration} has changed
+     * such that the device may be eligible for the installation of additional configuration splits.
+     * Configuration properties that can trigger this broadcast include locale and display density.
+     *
+     * <p class="note">
+     * Unlike {@link #ACTION_CONFIGURATION_CHANGED}, you <em>can</em> receive this through
+     * components declared in manifests. However, the receiver <em>must</em> hold the
+     * {@link android.Manifest.permission#INSTALL_PACKAGES} permission.
+     *
+     * <p class="note">
+     * This is a protected intent that can only be sent by the system.
+     *
+     * @hide
+     */
+    @SystemApi
+    @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_SPLIT_CONFIGURATION_CHANGED =
+            "android.intent.action.SPLIT_CONFIGURATION_CHANGED";
     /**
      * Broadcast Action: The current device's locale has changed.
      *
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index deefddb..af4a90c 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -53,6 +53,7 @@
     <protected-broadcast android:name="android.intent.action.UID_REMOVED" />
     <protected-broadcast android:name="android.intent.action.QUERY_PACKAGE_RESTART" />
     <protected-broadcast android:name="android.intent.action.CONFIGURATION_CHANGED" />
+    <protected-broadcast android:name="android.intent.action.SPLIT_CONFIGURATION_CHANGED" />
     <protected-broadcast android:name="android.intent.action.LOCALE_CHANGED" />
     <protected-broadcast android:name="android.intent.action.BATTERY_CHANGED" />
     <protected-broadcast android:name="android.intent.action.BATTERY_LOW" />
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 7d0f137..dd7c860 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -21936,7 +21936,7 @@
         }
         try {
             if (values != null) {
-                changes = updateGlobalConfiguration(values, initLocale, persistent, userId,
+                changes = updateGlobalConfigurationLocked(values, initLocale, persistent, userId,
                         deferResume);
             }
 
@@ -21954,8 +21954,16 @@
         return kept;
     }
 
+    /**
+     * Returns true if this configuration change is interesting enough to send an
+     * {@link Intent#ACTION_SPLIT_CONFIGURATION_CHANGED} broadcast.
+     */
+    private static boolean isSplitConfigurationChange(int configDiff) {
+        return (configDiff & (ActivityInfo.CONFIG_LOCALE | ActivityInfo.CONFIG_DENSITY)) != 0;
+    }
+
     /** Update default (global) configuration and notify listeners about changes. */
-    private int updateGlobalConfiguration(@NonNull Configuration values, boolean initLocale,
+    private int updateGlobalConfigurationLocked(@NonNull Configuration values, boolean initLocale,
             boolean persistent, int userId, boolean deferResume) {
         mTempConfig.setTo(getGlobalConfiguration());
         final int changes = mTempConfig.updateFrom(values);
@@ -22058,6 +22066,19 @@
                     UserHandle.USER_ALL);
         }
 
+        // Send a broadcast to PackageInstallers if the configuration change is interesting
+        // for the purposes of installing additional splits.
+        if (!initLocale && isSplitConfigurationChange(changes)) {
+            intent = new Intent(Intent.ACTION_SPLIT_CONFIGURATION_CHANGED);
+            intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING
+                    | Intent.FLAG_RECEIVER_INCLUDE_BACKGROUND);
+
+            // Typically only app stores will have this permission.
+            String[] permissions = new String[] { android.Manifest.permission.INSTALL_PACKAGES };
+            broadcastIntentLocked(null, null, intent, null, null, 0, null, null, permissions,
+                    OP_NONE, null, false, false, MY_PID, SYSTEM_UID, UserHandle.USER_ALL);
+        }
+
         // Override configuration of the default display duplicates global config, so we need to
         // update it also. This will also notify WindowManager about changes.
         performDisplayOverrideConfigUpdate(mStackSupervisor.getConfiguration(), deferResume,
@@ -22130,7 +22151,7 @@
                     // Override configuration of the default display duplicates global config, so
                     // we're calling global config update instead for default display. It will also
                     // apply the correct override config.
-                    changes = updateGlobalConfiguration(values, false /* initLocale */,
+                    changes = updateGlobalConfigurationLocked(values, false /* initLocale */,
                             false /* persistent */, UserHandle.USER_NULL /* userId */, deferResume);
                 } else {
                     changes = performDisplayOverrideConfigUpdate(values, deferResume, displayId);