Rename InputConnectionWrapper to RemoteInputConnection

This is a purely mechanical refactoring with no behavior change.

An existing non-API class

  com.android.internal.view.InputConnectionWrapper

has been used only from another non-API class

  android.inputmethodservice.IInputMethodWrapper.

By moving it to android.inputmethodservice package we can make it a
package-private class, which is what this CL is intended
to achieve.

Furthermore, there is another public API class with the same name:

  android.view.inputmethod.InputConnectionWrapper

, which has been confusing with this internal one.  To avoid such a
confusion, this CL also renames this internal one to
RemoteInputConnection.

Other than those mechanical changes, there should be no observable
behavior changes.

Bug: 192412909
Test: atest CtsInputMethodTestCases
Change-Id: Ic0babecd34a6bc80b917050370abc2db5c03d84e