Add maxTargetSdk restriction to IMM fields

CL[1] and CL[2] refined mCurId and mCurMethod into the
BindState, annotated them with deprecated.

This is a follow up change to add maxTargetSdk for these
UnsupportedAppUsage fields to be restricted android U.

[1]: I010bc0ad196492bfac244b756dcfd986b9075698
[2]: Ie29597118ab7f37d3f1ac2a5368b28f0462e7a0a

Bug: 236937383
Test: presubmit
Change-Id: I77859113768cb8545924e9e29473a20aa2f624c6