Skip documenttest for automotive

Sdk_gcar_x86 doesn't have documentUI package,
Thus supportsHardware() should return false, then
Document related tests in CtsAppSecurityHostTestCases
Should be skipped.

Bug: 139495480
Test: lunch sdk_gcar_x86-userdebug
Test: atest CtsAppSecurityHostTestCases
Change-Id: Iac52f47d7d6a8d1bac53fd7b3951a0ce0a9fb732