[Pod] Remove `set noparent` from pods/OWNERS.

That meant no one had owners on non-Android.bp files in pods/, which meant no one would be able to add a new pod :)

Bug: 307607958
Flag: EXEMPT OWNERS change
Test: N/A
Change-Id: I7df70a0d7e2ac6a3c0cb392603f44c6740298f98