Merge "Guard the usage of PacProxyManager when it is not supported by the device." am: 76f61bb2e8 am: 89c7b7db4e am: b92e07b760

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2623371

Change-Id: Iec75d57529f6eb0ac17c98650b4668cfeef1775c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>