Introduce new perf test for TextView with precomputed text

Here is an example of perf test result:

TextView new layout creation time:
  PrecomputedText           :    740,173
  PrecomputedText_Selectable: 17,727,649
  RandomText                : 17,130,685

TextView onDraw time:
  PrecomputedText           :  1,471,075
  PrecomputedText_Selectable: 31,971,393
  RandomText                : 17,667,572

TextView onMeasure time:
  PrecomputedText           :    177,669
  PrecomputedText_Selectable: 17,773,204
  RandomText                :  6,296,358

TextView setText (w/o layout creation) time:
  PrecomputedText           :     91,858
  PrecomputedText_Selectable:    152,665
  RandomText                :     11,130

Bug: 72998298
Test: ran perf test
Change-Id: I69af74ba743499bc444c441c1472fb19878c2eec