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

mobile/android/app/moz.build

@@ -0,0 +1,30 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+for var in ('APP_NAME', 'APP_VERSION'):
+    DEFINES[var] = CONFIG['MOZ_%s' % var]
+
+for var in ('MOZ_UPDATER', 'MOZ_APP_UA_NAME', 'ANDROID_PACKAGE_NAME'):
+    DEFINES[var] = CONFIG[var]
+
+for var in ('MOZ_ANDROID_GCM', ):
+    if CONFIG[var]:
+        DEFINES[var] = 1
+
+for var in ('MOZ_ANDROID_GCM_SENDERID', ):
+    if CONFIG[var]:
+        DEFINES[var] = CONFIG[var]
+
+if CONFIG['MOZ_PKG_SPECIAL']:
+    DEFINES['MOZ_PKG_SPECIAL'] = CONFIG['MOZ_PKG_SPECIAL']
+
+JS_PREFERENCE_PP_FILES += [
+     'mobile.js',
+]
+
+FINAL_TARGET_PP_FILES += [
+  'ua-update.json.in',
+]