Improve appearance of the Android preferences screen

* .gitignore: Add org/gnu/emacs/R.java.
* cross/Makefile.in (top_builddir): Include verbose.mk.  Rewrite
rules to print nice looking statements.
* doc/emacs/android.texi (Android, Android Startup)
(Android Environment, Android Windowing, Android Fonts):
* doc/emacs/emacs.texi (Top): Add an extra ``Android
Troubleshooting'' node and move troubleshooting details there.
* java/Makefile.in: Generate R.java; improve appearance by using
verbose.mk.

* java/org/gnu/emacs/EmacsPreferencesActivity.java: Reimplement
in terms of PreferencesActivity.
* java/org/gnu/emacs/EmacsView.java (handleDirtyBitmap): Avoid
flicker.
* java/res/xml/preferences.xml: New file.
* src/verbose.mk.in (AM_V_AAPT, AM_V_SILENT): New variables.

1 files changed, 28 insertions, 0 deletions

diff --git a/java/res/xml/preferences.xml b/java/res/xml/preferences.xml
new file mode 100644
index 00000000000..f0c3abb52e7
--- /dev/null
+++ b/java/res/xml/preferences.xml
@@ -0,0 +1,28 @@
+<!-- Descriptions for the preferences screen for GNU Emacs on Android.
+
+Copyright (C) 2023 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>. -->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+    <Preference android:key="start_quick"
+                android:title="Restart Emacs with -Q"
+                android:summary="Restart Emacs, but do not load site lisp or init files."/>
+
+    <Preference android:key="erase_dump"
+                android:title="Delete dump file"
+                android:summary="Remove the dumped state created when Emacs was installed"/>
+</PreferenceScreen>