Fine tune the UI about header message

We add horizontal padding on list mode for solving header message
moving issue when mode switch, but it still have some display issue.

Fix it only on header message layout, use different horizontal
padding to keep same position on both mode.

Bug: 134308835
Test: manual
Test: atest DocumentsUIGoogleTests
Change-Id: I0f5b0c92e42da8b6916961a5da97584b3d1d2fa0