Ensure that Thread(/*canCallJava*/ true) is attached to the VM.

This is supposed to be done by runtime, but when libutils is
dual-loaded with linker namespace, CreateThreadFunc should be
initialized separately within the namespace since libutils keeps
it in a global variable.

Test: build & boot & atest MediaPlayer2Test
Bug: 112766913
Change-Id: I23eac262c8b88178bf151d7c6ab49a48af932001