fix(voip): prevent stale MMKV cache on Android first-install accept

MMKVKeyManager.initialize ran in MainApplication.onCreate before the JS
engine started and opened the default MMKV file via the Tencent 1.2 JAR
when it was still empty. Tencent caches instances per-ID in a singleton
registry, so that empty-state view was held for the rest of the process.
JS later wrote credentials through react-native-mmkv (MMKV Core 2.0),
which has its own separate registry. When a VoIP push arrived,
Ejson.getMMKV() got the cached empty Tencent instance and reported
"No userId found in MMKV for server". Closing and reopening the app
cleared the cache, which is why only the very first call after install
failed.

Drop the open/verify block — the encryption key is already cached from
SecureKeystore, so no MMKV handle is needed here. The first Tencent
instance is now created inside Ejson.getMMKV() after JS has written,
so it scans the file fresh.

Author: diegolmello

android/app/src/main/java/chat/rocket/reactnative/storage/MMKVKeyManager.java

@@ -69,17 +69,17 @@ public static void initialize(Context context) {
                 Log.i(TAG, "Existing encryption key found");
             }
 
-            // Cache the encryption key for other native code
+            // Cache the encryption key for other native code.
+            // Do NOT open MMKV here: Tencent MMKV 1.2 (this JAR) caches instances
+            // per-ID in a singleton registry. Opening the file now — before JS has
+            // written anything — would cache an empty-state instance. When
+            // Ejson.java later reads via the same JAR, it gets that stale cached
+            // instance and misses writes made through react-native-mmkv (MMKV 2.0),
+            // which has its own separate registry. This manifests as the
+            // "No userId found in MMKV for server" failure on first install,
+            // resolved only by restarting the app (which clears the cache).
             encryptionKey = password;
-
-            // Verify MMKV can be opened with this key
-            MMKV mmkv = MMKV.mmkvWithID(DEFAULT_INSTANCE_ID, MMKV.SINGLE_PROCESS_MODE, password);
-            if (mmkv != null) {
-                long keyCount = mmkv.count();
-                Log.i(TAG, "MMKV initialized with encryption, " + keyCount + " keys found");
-            } else {
-                Log.w(TAG, "MMKV instance is null after initialization");
-            }
+            Log.i(TAG, "MMKV encryption key ready");
 
         } catch (Exception e) {
             Log.e(TAG, "MMKV encryption initialization failed", e);