base: Add simulate device connection Java APIs

Expose the setSimulateDeviceConnections to Java Layer. It can be
helpful during the testing.

Test: make and check logs
Bug: 401100433
Flag: EXEMPT TestApi

(cherry picked from https://android-review.googlesource.com/q/commit:6dd9828373ebeb58a467a11f40107117abd6aecd)
Change-Id: I15eb872da75a68c06a343f22aee52bfad2fc43a7