Build warnings

[cyb3rko]

Shouldn't be too hard to fix.
The deprecations require some refactoring into new framework functions.

w: file:///[...]gotify/#/#Activity.kt:155:13 'startActivityForResult(Intent, Int): Unit' is deprecated. Deprecated in Java
w: file:///[...]gotify/#/#Activity.kt:166:15 'onActivityResult(Int, Int, Intent?): Unit' is deprecated. Overrides deprecated member in 'androidx.activity.ComponentActivity'. Deprecated in Java
w: file:///[...]gotify/messages/MessagesActivity.kt:249:19 'onBackPressed(): Unit' is deprecated. Overrides deprecated member in 'androidx.core.app.ComponentActivity'. Deprecated in Java
w: file:///[...]gotify/messages/MessagesModelFactory.kt:12:75 Unchecked cast: MessagesModel! to T
w: file:///[...]gotify/service/WebSocketConnection.kt:204:51 'getter for activeNetworkInfo: NetworkInfo?' is deprecated. Deprecated in Java
w: file:///[...]gotify/service/WebSocketConnection.kt:205:49 'getter for isConnected: Boolean' is deprecated. Deprecated in Java
w: file:///[...]gotify/settings/SettingsActivity.kt:113:28 'setTargetFragment(Fragment?, Int): Unit' is deprecated. Deprecated in Java

/home/runner/[...]res/values/strings.xml:39:4: Multiple substitutions specified in non-positional format of string resource string/other_error. Did you mean to add the formatted="false" attribute?
/home/runner/[...]res/values/strings.xml:5:4: Multiple substitutions specified in non-positional format of string resource string/version_failed. Did you mean to add the formatted="false" attribute?
/home/runner/[...]res/values/strings.xml:61:4: Multiple substitutions specified in non-positional format of string resource string/version_failed_status_code. Did you mean to add the formatted="false" attribute?
/home/runner/[...]res/values/strings.xml:66:4: Multiple substitutions specified in non-positional format of string resource string/versions. Did you mean to add the formatted="false" attribute?

[cyb3rko]

The last warning of the code build (SettingsActivity) has to be suppressed for now according to a Google employee.
Source: https://issuetracker.google.com/issues/181793702#comment3

[cyb3rko]

I've already fixed most of them. What's left is the unchecked cast and the NetworkInfo deprecation.

My suggestions:

• Unchecked cast: Suppress the warning, what else should we do here?
• NetworkInfo deprecations: The recommended newer way to go is using a listener for network changes. But I believe just checking the current network info is enough here, a listener would not be helpful in my opinion. So also suppress?

What do you think @jmattheis ?

[jmattheis]

Suppressing the warning looks ok. It's also done so in this android docs.

The network info is only used for logging in the websocket service, we can probably remove this, as it isn't really needed.