Fix a bug where homepage is using staled locale for tiles

When setting a new locale, SettingsActivity restarts to load
everything in the new locale.

Data (containing locale specific title/summary etc) is reloaded
correctly and triggers a callback to UI to redraw.

However we skip the first callback as an optimization for app startup
time. When we restart fragment, we failed to save the state whether we
have already seen the first callback. So when data with new locale text
triggers the callback, it's being skipped and this make UI still render
in old locale.

The fix is to just save the state before fragment gets destroyed before
locale change so the callback can trigger later.

A better fix is: make data (Tile object) not cache text. Then we don't
need to worry about locale cache at all. We should do this fix in the
long term.

Test: localeswitcher
Test: adb shell am broadcast -a com.google.android.testing.i18n.localeswitcher.CHANGE_LOCALE -e LANGUAGE_TAG "zh"
Test: adb shell am broadcast -a com.google.android.testing.i18n.localeswitcher.CHANGE_LOCALE -e LANGUAGE_TAG "ja"

Fixes: 77470788
Bug: 77600770

Change-Id: Ic4223ddbb679db64d0fc3c29d16a5f61a66cc99c