Allow the popup to gracefully handle activity destruction

Currently, on activity destruction, sometimes the popup would still be
alive (e.g. on configuration change). So, in that case, on activity
destruction, save the popup state and manually dismiss it. Then on next
init, restore the state.

Bug: 407675188
Test: atest 'DocumentsUIGoogleTests:com.android.documentsui.JobPanelUiTest'
Flag: com.android.documentsui.flags.visual_signals_ro
Change-Id: I3f6af9fa35bfd980b87cb76515ad668a38f86f34