AOSP builds do not support Device ID attestation

AOSP builds have different product & brand values than the ones flashed
onto the device's Keymaster in the factory.
As a result, Device ID attestation will not work on them correctly
because there is a mismatch between the values sent to Keymaster by the
platform and the values Keymaster is expecting to attest to.

Mark AOSP builds as not having this feature since it would affect all
AOSP builds on all devices.

Bug: 110361822
Test: atest com.android.cts.devicepolicy.MixedDeviceOwnerTest#testKeyManagement
Change-Id: I55e7c68b3e082af465c19cf18aeeeecffc4eb356