chore(mobile): bump Android versionCode to 17 for the 0.0.50 release (#21335)

versionCode 16 already shipped as mobile-android-v0.0.48, and Android
refuses an install whose versionCode is not higher than the installed
one. Keep expo.version at 0.0.50 so the release tag can match it.

mobile/app.json

@@ -75,7 +75,7 @@
       "allowBackup": false,
       "permissions": ["RECORD_AUDIO", "MODIFY_AUDIO_SETTINGS"],
       "package": "com.stably.orca.mobile",
-      "versionCode": 16,
+      "versionCode": 17,
       "googleServicesFile": "./google-services.json"
     },
     "plugins": [