Require coordinate transformation matrix if necessary

With this CL, CursorAnchorInfo.Builder#build() raises
IllegalArgumentException when an application author attempts to
instantiate CursorAnchorInfo without the coordinate
transformation matrix but with specifying some positional
parameters such as composing character rectangle.

Since any other positional members in CursorAnchorInfo are
supposed to be specified in local coordinates, the application
author must provide the coordinate transformation matrix for
such positional data.

Change-Id: I2b0fd0f146a2b95fe4fa1324837d8cfee667208c