Rationalized the single/multiple line initialization in TextViews.

The TYPE_TEXT_FLAG_MULTI_LINE was set directly, instead of calling
setSingleLine, which has some side effects, like correctly updating
the mSingleLine field.

Generalized the use of setSingleLine everywhere. This may change some
behavior, but is probably fixing more state inconsistencies.

Change-Id: I6b4da2e140a8dc75481cff9e44473daa6b3a83c4