pt 1 in reviving the android build (copied from pm 28a1, wish me luck)

mobile/android/base/java/org/mozilla/gecko/PackageReplacedReceiver.java

@@ -0,0 +1,38 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.util.Log;
+
+import org.mozilla.gecko.mozglue.GeckoLoader;
+
+/**
+ * This broadcast receiver receives ACTION_MY_PACKAGE_REPLACED broadcasts and
+ * starts procedures that should run after the APK has been updated.
+ */
+public class PackageReplacedReceiver extends BroadcastReceiver {
+    public static final String ACTION_MY_PACKAGE_REPLACED = "android.intent.action.MY_PACKAGE_REPLACED";
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        if (intent == null || !ACTION_MY_PACKAGE_REPLACED.equals(intent.getAction())) {
+            // This is not the broadcast we are looking for.
+            return;
+        }
+
+        // Extract Gecko libs to allow them to be loaded from cache on startup.
+        extractGeckoLibs(context);
+    }
+
+    private static void extractGeckoLibs(final Context context) {
+        final String resourcePath = context.getPackageResourcePath();
+        GeckoLoader.loadMozGlue(context);
+        GeckoLoader.extractGeckoLibs(context, resourcePath);
+    }
+}