Remove all instances of file names from ActivityTestJunit4

With the move to the TestFilesRule, these should be referenced through
there and not via the ActivityTestJunit4. Remove them and update all
the references.

This also fixes up an indentation issue in SearchViewUiTest.

Bug: 407646510
Test: atest DocumentsUIGoogle
Flag: EXEMPT test change
Change-Id: I2445d3a9d43ca43b5170bfc8fab80aeca74bc040