base

Fix regression in CursorWindow.getString()
Bug: 5332296

NewStringUTF expects modified UTF-8, so it barfs on UTF-8 strings
that contain high codepoints.  Even though it results in an extra
copy being performed, first convert to UTF-16, then call NewString.

Change-Id: Idbfeb3cc2c4b731834e4482848dcac2fa33ec2d0