Adding new A11y window type to A11y services

Two window types, INPUT_METHOD and INPUT_METHOD_DIALOG are group
into a single A11y window type, TYPE_INPUT_METHOD, at A11y
framework such that A11y services could not do correct behavior
when the input method dialog shows. Splitting out the
INPUT_METHOD_DIALOG and mapping it to TYPE_APPLICATION to fix
this issue.

Bug: 154315649
Test: a11y CTS & unit tests
Change-Id: I263398b20e75f48afebbe8d002994a00a110abdc