Require native Git runtime and bundle full manpages

- Remove the app fallback path when native Git is unavailable and show a startup blocker instead
- Fix native level setup for staged file counting and cherry-pick parity
- Improve manpage loading/search and bundle full Git documentation assets
- Integrate Git cross-compilation into AndroidProjectTooling.sh and remove debug AAB support

app/src/main/assets/manpages/git-credential-cache--daemon.txt

@@ -0,0 +1,30 @@
+git-credential-cache{litdd}daemon(1)
+====================================
+
+NAME
+----
+git-credential-cache--daemon - Temporarily store user credentials in memory
+
+SYNOPSIS
+--------
+[verse]
+'git credential-cache{litdd}daemon' [--debug] <socket-path>
+
+DESCRIPTION
+-----------
+
+NOTE: You probably don't want to invoke this command yourself; it is
+started automatically when you use linkgit:git-credential-cache[1].
+
+This command listens on the Unix domain socket specified by `<socket-path>`
+for `git-credential-cache` clients. Clients may store and retrieve
+credentials. Each credential is held for a timeout specified by the
+client; once no credentials are held, the daemon exits.
+
+If the `--debug` option is specified, the daemon does not close its
+stderr stream, and may output extra diagnostics to it even after it has
+begun listening for clients.
+
+GIT
+---
+Part of the linkgit:git[1] suite