android: the keep rules for a release build nobody has made

Every APK this port has produced is `assembleArm64Debug`, and the generated
project turns R8 on for `release` and only for `release` — while tauri finds a
plugin class by string, files every `@Command` under `commands[method.name]`,
and lets Jackson fill every `@InvokeArg` field by field. Minification breaks
exactly that, and it breaks it without a word: the app compiles, installs,
launches, shows Home, and then a tap on Library folder answers "No command
pickFolder found for plugin ..." in logcat and nothing on screen. So each
plugin module now carries its own `consumer-rules.pro` naming its own
reflected surface — the shape tauri-android and tauri-plugin-dialog already
use in this build, and one that travels with the plugin into a regenerated
`gen/android`, which a rule written into that gitignored tree would not.

What belongs to no single plugin is in `src-tauri/android/proguard-soulstream.pro`,
copied into the generated project by the build script because the app's own
Gradle file is regenerated: the runtime annotation attributes, a `-dontwarn`
pair for the two `java.beans` classes jackson-databind references and Android
does not have (R8 turns a missing class into a build error, so without them
there may be no APK at all), and a keep for the four `@Command` methods
declared on `app.tauri.plugin.Plugin` itself. Tauri's own rule matches classes
annotated `@TauriPlugin` and the members they declare; the base class carries
no such annotation, so nothing names `registerListener` — which is what the
lock-screen card's buttons and the download notice's Cancel and Open ride on.

`build.sh` grows `--release`: the release profile, `--features tauri/devtools`
so the walk can still attach at all, `assembleArm64Release`, and a zipalign and
sign with the same debug key the phone already trusts, so the APK installs over
the app rather than forcing an uninstall that would take Kyle's settings with
it. With no argument the script is what it has always been, cargo line for
cargo line, so deploy.sh and ship.sh keep the path they run every twenty
minutes. None of this has been built: Gradle, Kotlin and R8 do not run on this
machine, the rules are a precaution against a silent failure rather than a fix
for an observed one, and ANDROID.md says so and lists what to test by hand,
command by command, on the first release build anyone makes.