Add auto-discovery of LSPosed-scoped apps via ContentProvider

Manually re-typing a package name Veil already got injected into was
redundant work. The hook now reports "I got loaded into package X" to a
small ContentProvider in Veil's own app the moment a scoped app's process
starts (found via hooking Application#attach for a reliable early Context),
which records it to SharedPreferences. Veil's settings screen lists the
union of explicitly configured apps and auto-detected ones, tagging the
latter so it's clear they haven't been customized yet.

No persistent service: the OS starts Veil's process on demand for each
call() and can kill it again right after, same footprint as everything
else in this module.

Co-Authored-By: agent <agent@bdeshi.space>

app/src/main/AndroidManifest.xml

@@ -25,5 +25,10 @@
             </intent-filter>
         </activity>
 
+        <provider
+            android:name=".VeilProvider"
+            android:authorities="space.bdeshi.veil.provider"
+            android:exported="true" />
+
     </application>
 </manifest>