Fix CtsApacheHttpLegacy27ApiSignatureTestCases:SignatureTests

Set InputMethod.updateInputMethodDisplay as default method for fixing API
check.
Since this method is @hide & we don't want to enforece user to implement.

Bug: 116662257
Bug: 111364446
Test: atest CtsApacheHttpLegacy27ApiSignatureTestCases:SignatureTest#testSignature

Change-Id: Ifb136d86d19bc4f95154a9076d42326ce12f665f