Release Android Preview 21 and bilingual changelog

Add permission-based reading of Android contacts, SMS and call history. Include shared Gaia fixes and document device validation limits. Pixel image qualification remains pending.

tests/keyboard-startup.test.mjs

@@ -0,0 +1,40 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import vm from 'node:vm';
+import {readFileSync} from 'node:fs';
+
+const source=readFileSync(new URL('../host/gaia-input.js',import.meta.url),'utf8');
+function keyboard() {
+  const listeners=new Map();let reply;
+  const parent={postMessage(){}};
+  const context={VulpesNativeInput:true,location:{hostname:'keyboard.localhost'},
+    VulpesCompat:{call:()=>new Promise(resolve=>reply=resolve)},
+    navigator:{},document:{readyState:'loading'},parent,console,Event,EventTarget,
+    CustomEvent:class extends Event {constructor(name,options){super(name);this.detail=options.detail;}},
+    addEventListener(name,fn){listeners.set(name,fn);},dispatchEvent(){}};
+  context.window=context;
+  vm.runInNewContext(source,context);
+  return {
+    ime:context.navigator.mozInputMethod,
+    state:value=>listeners.get('vulpes-service-event')({detail:{type:'input-focus',data:value}}),
+    reply:value=>reply(value),
+    viewport:()=>listeners.get('message')({source:parent,origin:'http://system.localhost:8765',
+      data:{type:'vulpes-keyboard-viewport',width:360,height:740}})
+  };
+}
+test('an old empty snapshot cannot clear a newly focused keyboard',async()=>{
+  const k=keyboard();k.viewport();k.state({id:2,text:'current'});k.reply(null);
+  await new Promise(resolve=>setImmediate(resolve));
+  assert.equal(k.ime.inputcontext.text,'current');
+});
+test('an old active snapshot cannot reopen a dismissed keyboard',async()=>{
+  const k=keyboard();k.viewport();k.state(null);k.reply({id:1,text:'old'});
+  await new Promise(resolve=>setImmediate(resolve));
+  assert.equal(k.ime.inputcontext,null);
+});
+test('focus received before viewport measurement survives a stale initial reply',async()=>{
+  const k=keyboard();k.state({id:3,text:'pending'});k.reply(null);
+  await new Promise(resolve=>setImmediate(resolve));
+  k.viewport();
+  assert.equal(k.ime.inputcontext.text,'pending');
+});