Fix ascent and descent of Droid Sans Mono to match Roboto.

Fix ascent and descent of Droid Sans Mono to match Roboto.

Previously, the inconsistency resulted in test in the testUniformY in
frameworks/base/graphics/tests/graphicstests/src/android/graphics/TypefaceTest.java
fail. The tests assume the different sans/serif/mono styles share a
consistent ascent and descent.

The font is modified using the following Python script:

from fontTools import ttLib

font_file = 'DroidSansMono.ttf'
font = ttLib.TTFont(font_file)
font['hhea'].ascent = 1900
font['hhea'].descent = -500
font.save('touched/'+font_file)

Bug: 19791102
Change-Id: I2fcd44b952691deeeed18f30d06bc9f6d5e4a8de