Since a fullscreen IME covers the entire search dialog, there was no discoverable way to get back to the search dialog. Now, on BACK presses when the IME is fullscreen (e.g. in landscape mode without hard keyboard), we dismiss only the IME. A second BACK press will dismiss the search dialog. Fixes http://b/issue?id=2159132 Change-Id: I8e5736d83d7c35936a718929017ea04c6214700b