Remove IME switcher revamp API tests

In [1], the API changes of IME switcher revamp were extracted
to the IME_SWITCHER_REVAMP_API flag. However, some newer builds
with this change are ran on older versions of CTS that won't
see the new feature flag, thus we should remove the tests on
these older branches only.

  [1]: If2459ff0e6b00e3001d4c60664d7a8c631447932

Test: atest
  InputMethodInfoTest#testEquals
  InputMethodInfoTest#testInputMethodInfoProperties
  InputMethodInfoTest#testInputMethodInfoWriteToParcel
Bug: 311791923
Bug: 358064940
Flag: android.view.inputmethod.ime_switcher_revamp_api
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ba40b64683d95e7940f9811e561c75843dc01ced)
Merged-In: I35c4c5dfaa9ebdf4385296561ee21ad9d84adffe
Change-Id: I35c4c5dfaa9ebdf4385296561ee21ad9d84adffe