fix(android): notification Bundles with non-string values

[frederikbosch]

The method getDeliveredNotifications() throws because getString(key) is called on notification.extras but the extras Bundle object contains more than just strings. Booleans cannot be casted to string, see the exception stack trace below.

Key android.progressIndeterminate expected String but value was a java.lang.Boolean.  The default value <null> was returned. 
Attempt to cast generated internal exception:
    java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.lang.String
        at android.os.BaseBundle.getString(BaseBundle.java:1448)
        at com.capacitorjs.plugins.pushnotifications.PushNotificationsPlugin.getDeliveredNotifications(PushNotificationsPlugin.java:147)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.getcapacitor.PluginHandle.invoke(PluginHandle.java:138)
        at com.getcapacitor.Bridge.lambda$callPluginMethod$0(Bridge.java:837)
        at com.getcapacitor.Bridge.$r8$lambda$FNYM7cvgeBk0k8YXQH7M96Mrf-c(Unknown Source:0)
        at com.getcapacitor.Bridge$$ExternalSyntheticLambda0.run(D8$$SyntheticClass:0)
        at android.os.Handler.handleCallback(Handler.java:995)
        at android.os.Handler.dispatchMessage(Handler.java:103)
        at android.os.Looper.loopOnce(Looper.java:273)
        at android.os.Looper.loop(Looper.java:363)
        at android.os.HandlerThread.run(HandlerThread.java:85)

[OS-pedrogustavobilro]

Hey @frederikbosch thanks for the PR, I took the liberty of replicating the same change in local-notifications plugin.

I wasn't able to trigger a notification with non-string values, but can force-replicate the error in code, and since the data/extra types in the plugin API is any, I see no reason not to merge the PR.

[frederikbosch]

@OS-pedrogustavobilro Sure, go ahead and replicate in local notifications.