[Thread] rename requestThreadNetwork to registerThreadNetworkCallback am: 0ffdc107e7 am: ba7cd0b9b9

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3265031

Change-Id: I2b12f98878fb1c74b7755c7e47bb2489ac6f2395
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>