Add selectable text view perf test for random text

The performance characteristics are quite different if selection is
enabled. Good to add selectable random text case for reference.

This CL also fixes makeMeasureSpec miss usage.

android.widget.TextViewPrecomputedTextPerfTest:
    newLayout_PrecomputedText           :    758,899
    newLayout_PrecomputedText_Selectable: 17,923,065
    newLayout_RandomText                : 17,059,504
    newLayout_RandomText_Selectable     : 18,523,234
    onDraw_PrecomputedText              :  4,097,640
    onDraw_PrecomputedText_Selectable   : 17,733,448
    onDraw_RandomText                   : 17,941,208
    onDraw_RandomText_Selectable        : 18,948,912
    onMeasure_PrecomputedText           :    781,546
    onMeasure_PrecomputedText_Selectable: 18,423,652
    onMeasure_RandomText                : 18,067,749
    onMeasure_RandomText_Selectable     : 19,364,439
    setText_PrecomputedText             :     91,383
    setText_PrecomputedText_Selectable  :    161,088
    setText_RandomText                  :     11,142
    setText_RandomText_Selectable       :     54,596

Bug: 72998298
Test: N/A
Change-Id: I8c04fd972897eb804be42adff883df13d87bf11e