DoH: Change to use runtime with current thread scheduler in doh_query() am:...

DoH: Change to use runtime with current thread scheduler in doh_query() am: 42a73532 am: 6b8f8092 am: 3ba12b46 am: 6f7a360c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/1936192

Change-Id: I9ae72c2067b402916d7caca06626c7bfd968a7d6