Undo changes to DEFAULT_ACCEPTABLE_BOOT_VERSIONS

This partially reverts If1041ca98441889360de3623bfe5024ce4fe5a2f,
now that we have JDK11 prebuilts we don't need to bootstrap with
JDK9.

Bug: 205944740
Test: openjdk build
Change-Id: I84c1871e01e1c66bbd4696423072416cfcb69104
1 file changed