ANDROID: Revert "Enable '-Werror' by default for all kernel builds"

This reverts commit 3fe617cc.

Right now the android build system can not work properly for some of the
builds forcing this option on for them as they still have warnings.

So revert it for now, we will remove this later on, hopefully before
5.15-final is out, after all of the build warnings are cleaned up.

Bug: 199872592
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I7e6a0ebb76ab2876cb180214911c1c25b0904a23