* admin/admin.el (admin-android-version-code-regexp): New
variable.
(set-version): Modify AndroidManifest.xml.in instead.

* java/AndroidManifest.xml.in (Version-code): Define version
code.

* java/incrementing-version-code: Delete file.

The version code is intended to be an integer that increments
for each Android package release
(https://developer.android.com/studio/publish/versioning#versioningsettings).

If we keep this updated under version control, then F-Droid (a
third-party Android package repository), can watch for that, and
use it to automatically build Emacs packages for Android each
time a new Emacs release is tagged
(https://f-droid.org/en/docs/Build_Metadata_Reference/#UpdateCheckData).

* admin/admin.el (set-version): Update version code in
java/incrementing-version-code
* java/incrementing-version-code: New file containing an Android
version code corresponding to the current Emacs version.
(bug#75809)