AttachmentMediaActivity crashes in onStart when the url extra is null

[stevePanella]

Describe the bug
AttachmentMediaActivity crashes with a NullPointerException when it's started without a url extra. onCreate catches the null url, logs "This file can't be displayed", and shows the playback error, but binding is already initialized by then. So onStart gets past its ::binding.isInitialized check and calls Uri.parse(url) with null.

java.lang.NullPointerException: uriString
    at android.net.Uri$StringUri.<init>(Uri.java:496)
    at android.net.Uri$StringUri.<init>(Uri.java:486)
    at android.net.Uri.parse(Uri.java:458)
    at io.getstream.chat.android.ui.feature.gallery.AttachmentMediaActivity.onStart(AttachmentMediaActivity.kt:95)
    at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1674)
    at android.app.Activity.performStart(Activity.java:8018)
    at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3469)

The same code is still in 7.13.0 and on develop.

SDK version

• 7.3.0 (also present in 7.13.0)

To Reproduce
We don't know the exact user steps that end up with a null url, since AttachmentDestination passes assetUrl ?: "". You can hit the crash directly by starting the activity without the extra:

1. On an emulator: adb root, then
   adb shell am start -n <your.app.id>/io.getstream.chat.android.ui.feature.gallery.AttachmentMediaActivity --es type video
2. See the crash in onStart

Expected behavior
The activity doesn't crash when the url extra is null.

Device:

• Vendor and model: Honor HRY-LX1T, OnePlus 8 Pro, OnePlus A0001
• Android version: 11

Screenshots
N/A