Avoid changing global compute mode in UnknownDimensionsTest.

Prior to this CL, UnknownDimensionsTest will set and restore global
compute mode. The restore may not be executed if ASSERT_EQ failed and
causing the subsequent tests executing with a wrong compute mode. This
CL avoids this issue by passing a temporary compute mode to
test_wrapper::Execution::compute.

Bug: 186908383
Test: NNT_static
Change-Id: I34af78a1699c33490479e1d0b2c0a535f5abb664
Merged-In: I34af78a1699c33490479e1d0b2c0a535f5abb664
(cherry picked from commit 1f0d3aafd99ecc08e1a6e13668735ba52b3b24ba)
1 file changed