Remove redundant bindSequence logic in IMM

Remove a redundant code logic added by CL[1] when
handling the MSG_BIND_ACCESSIBILITY_SERVICE message.

Because we already early return when mBindSequence
is not equal to res.sequence.

[1]: Ia651a811093a939d00c081be1961e24ed3ad0356

Fix: 237980344
Bug: 236920321
Test: atest CtsInputMethodTestCases
Change-Id: I50fbebde0abe07faac68b0ba4f9ea30199a28df5