cargo2android: reorder TEST_MAPPING statements

"host: true" entry should go before "name:" to match the output of
json writers which sort by alphabetical order. This will help and
avoid unnecesary changes when adding new tests to TEST_MAPPING - e.g.
aosp/1488728

Bug: 168167373
Test: cargo2android.py --run --tests
verify output

Change-Id: Id346a7f8a2cd910115e7fcc448c589363209bee9
1 file changed