Fix DatePicker rendering.

1. Return AccessibilityManager service from context.
2. Don't throw an exception if no style specifited in
obtainStyledAttributes. Specifying no style is valid and it's supposed
to use the default theme in that case.

Bug: http://b.android.com/82712 and http://b.android.com/79218
Change-Id: Iba7097f36996e4d6f1e9db778dc73294f2854c79
1 file changed