Don't add unused properties to android_test_import

android_test_import is to import prebuilt test apks into the build rule.
It doesn't support properties like test_config, test_config_template,
and etc, but those properties were anyhow added to the module type and
setting those properties didn't trigger any error.

Fixing this surprising behavior by adding only the properties that are
actualy being used.

Bug: N/A
Test: N/A

Change-Id: I93e821e108861fa1249bc5e0882d706849bcf43f