Clear the URL bar if this file type is unsupported.

[daoshengmu]

Fixes #3248.

I hope using postValue() is right instead of setValue()

[keianhzo]

When you are is a website and you try to open the file, the URL bar is cleared. I think we should fix it just removing the setUrl call from:

FirefoxReality/app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/WindowWidget.java

Lines 1729 to 1732 in 12726e0

	public void onPageStart(@NonNull GeckoSession geckoSession, @NonNull String aUri) {
	mCaptureOnPageStop = true;
	mViewModel.setUrl(aUri);

as we are already updating in:

FirefoxReality/app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/WindowWidget.java

Lines 1751 to 1752 in 12726e0

	public void onLocationChange(@NonNull GeckoSession session, @Nullable String url) {
	mViewModel.setUrl(url);

That should fix it.

[daoshengmu]

It works as you said. Thanks.

Requested change was made.