Fix restoreSearch behavior

If there has checked chip, when the user rotates the device,
the search field will expand due to restoreSearch method.
The function is only used to restore text search.
Refactor it and also rename the method to avoid confusion.

Fix: 124911175
Test: manual
Test: atest DocumentsUITests
Change-Id: I0b61bb3cdf3373173b1d8ec7c270a5e8a16ed09b