Improve search UI

[domdomegg]

Description (required)

Fixes

• "Search commons" text not being at the same horizontal alignment of all the other activities
• Action bar being white, while all other activities have it as blue

Tests performed (required)

Tested 2.9.0-debug-improve-search-ui~895d8a97d on Galaxy Nexus (emulator) with API level 28.
Tested 2.9.0-debug-improve-search-ui~895d8a97d on Galaxy Nexus (emulator) with API level 25.
Tested 2.9.0-debug-improve-search-ui~895d8a97d on Samsung Galaxy S6 with API level 25.

Screenshots showing what changed

Before	After
https://giphy.com/gifs/uBmSMFrRgIHuIJTYvx	https://giphy.com/gifs/ctNcQJ2DtHiFKexuGe

[codecov-io]

Codecov Report

Merging #2189 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #2189   +/-   ##
======================================
  Coverage    5.71%   5.71%           
======================================
  Files         231     231           
  Lines       11595   11595           
  Branches     1079    1079           
======================================
  Hits          663     663           
  Misses      10877   10877           
  Partials       55      55

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[neslihanturan]

Thanks @domdomegg tested both on dark and light theme, looks very nice.