fix(ios) make sure broadcast extension version matches

Fixes this Apple Store Connect warning:

~~~
ITMS-90473: CFBundleShortVersionString Mismatch - The CFBundleShortVersionString
value '1.0' of extension 'jitsi-meet.app/PlugIns/JitsiMeetBroadcast
Extension.appex' does not match the CFBundleShortVersionString value '21.0.0' of
its containing iOS application 'jitsi-meet.app'.
~~~

ios/app/broadcast-extension/Info.plist

 	<key>CFBundlePackageType</key>
 	<string>$(PRODUCT_BUNDLE_PACKAGE_TYPE)</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0</string>
+	<string>21.0.0</string>
 	<key>CFBundleVersion</key>
 	<string>1</string>
 	<key>NSExtension</key>

resources/update-mobile-version.sh

 
 # iOS
 /usr/libexec/PlistBuddy -c "Set :CFBundleShortVersionString ${VERSION}" ${THIS_DIR}/../ios/app/src/Info.plist
+/usr/libexec/PlistBuddy -c "Set :CFBundleShortVersionString ${VERSION}" ${THIS_DIR}/../ios/app/broadcast-extension/Info.plist
 /usr/libexec/PlistBuddy -c "Set :CFBundleShortVersionString ${VERSION}" ${THIS_DIR}/../ios/app/watchos/app/Info.plist
 /usr/libexec/PlistBuddy -c "Set :CFBundleShortVersionString ${VERSION}" ${THIS_DIR}/../ios/app/watchos/extension/Info.plist