Update to RingRTC v2.9.4

app/build.gradle

@@ -334,7 +334,7 @@ dependencies {
     implementation 'com.google.protobuf:protobuf-javalite:3.10.0'
     implementation 'org.signal:argon2:13.1@aar'
 
-    implementation 'org.signal:ringrtc-android:2.9.2'
+    implementation 'org.signal:ringrtc-android:2.9.4'
 
     implementation "me.leolin:ShortcutBadger:1.1.22"
     implementation 'se.emilsjolander:stickylistheaders:2.7.0'

app/witness-verifications.gradle

@@ -414,8 +414,8 @@ dependencyVerification {
         ['org.signal:argon2:13.1',
          '0f686ccff0d4842bfcc74d92e8dc780a5f159b9376e37a1189fabbcdac458bef'],
 
-        ['org.signal:ringrtc-android:2.9.2',
-         'baf77e1f314dce89278af205637d607dbf4607651dee02384f111f43fea29cf6'],
+        ['org.signal:ringrtc-android:2.9.4',
+         'd4d26b26b096c553966f77229b3f7a0d3704d88caf9caca937388cff054f5257'],
 
         ['org.signal:zkgroup-android:0.7.0',
          '52b172565bd01526e93ebf1796b834bdc449d4fe3422c1b827e49cb8d4f13fbd'],