Fix a bug with some text fields

Not sure when this happens exactly, but it is possible that
InputConnection#getTextBeforeCursor returns null. This
happens for example upon rotating the screen with the
composing field empty in Gmail.
In this case, StringBuilder#append will convert the null
pointer into the string "null", which is sure better than a
crash, but can have a number of bad side-effects, like
auto-caps not working.

Bug: 7533034
Change-Id: Ia1cfab432c13a12ff1c2f013c59bac05a587f553
1 file changed
tree: 6a1e2db0a59592076c3c7d010a37f5e12ab4caf8
  3. dictionaries/
  4. java/
  5. native/
  6. tests/
  7. tools/