iris: AndroidAppState::platform_ready, a JavaVM+View handle for later JNI calls

Default no-op lifecycle hook, called once from new_peer right after new.
P0's bench build needs to call BatteryManager/ClipboardManager through the
view's own Context from a background thread as well as the UI thread, and
neither a JavaVM nor a GlobalRef to the view was reachable from
AndroidAppState::new before this. Existing implementors (Client,
TranscriptClient) are unaffected.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

iris/src/android/view.rs

@@ -4,7 +4,7 @@ use accesskit_android::Adapter as AccessAdapter;
 use android_view::{
     AccessibilityNodeInfo, AccessibilityNodeProvider, Bundle, CallbackCtx, Context,
     InputConnection, KeyEvent, MotionEvent, Rect, View, ViewPeer,
-    jni::{JNIEnv, sys::jint},
+    jni::{JNIEnv, JavaVM, objects::GlobalRef, sys::jint},
     ndk::event::{Keycode, MotionAction},
 };
 // `marker::Sized` explicitly: `crate::prelude::*` below also brings in the
@@ -107,6 +107,19 @@ pub trait AndroidAppState: HasAndroidUiState {
     fn back_pressed(&mut self, rsc: &mut AndroidRsc<Self>, render: &mut UiRenderState) -> bool {
         false
     }
+    /// Called once, right after `new`, with a fresh `JavaVM` handle and a
+    /// global reference to this app's own `View` -- for a caller that
+    /// needs to call into Java itself beyond what a [`RequestRedraw`]
+    /// handle already covers (P0's bench build calling
+    /// `BatteryManager`/`ClipboardManager` through the view's `Context`,
+    /// docs/RUST.md). Not folded into `new` itself: most implementors need
+    /// nothing here, and `new`'s job is building the widget tree, not
+    /// holding a platform handle -- the default does nothing. `vm`/`view`
+    /// are independent handles from the ones `new_peer` keeps for its own
+    /// `RequestRedraw` (a fresh `get_java_vm`/`new_global_ref` each), so
+    /// storing them has no effect on that mechanism.
+    #[allow(unused_variables)]
+    fn platform_ready(&mut self, rsc: &mut AndroidRsc<Self>, vm: JavaVM, view: GlobalRef) {}
 }
 
 /// The android-view analogue of `default::DefaultRsc` -- identical in
@@ -561,7 +574,10 @@ pub fn new_peer<'local, State: AndroidAppState>(
     };
     let shared = Rc::new(RefCell::new(Shared::default()));
     let ui_state = AndroidUiState::new(shared.clone());
-    let state = State::new(ui_state, &mut rsc);
+    let mut state = State::new(ui_state, &mut rsc);
+    let platform_vm = env.get_java_vm().unwrap();
+    let platform_view = env.new_global_ref(&view.0).unwrap();
+    state.platform_ready(&mut rsc, platform_vm, platform_view);
     let peer = IrisViewPeer {
         rsc,
         render: UiRenderState::new(),