ARM64: Fix the CallOtherJustTooFarAfter test.

Fix ARM64 relative patcher test CallOtherJustTooFarAfter
depending on the size of OatQuickMethodHeader being at
least kArm64Alignment. This is needed for
    https://android-review.googlesource.com/708891
that removes some members from the OatQuickMethodHeader.

Test: m test-art-host-gtest-relative_patcher_arm64_test
Test: Cherry-pick the above CL PS5 and repeat the gtest.
Change-Id: I01074aee41217f7aba10af13bcbc17dafcc03f43