adb: replace `if(transportType==` with `switch(transportType)`

Use switch on transportType to provision
adding more enum cases. No behavior change.

Bug: 402444824
Test: adb still works
Flag: EXEMPT cleanup
Change-Id: I06dfa5162ca8697a9bdc24547495067df2b58087
Signed-off-by: Roman Kiryanov <rkir@google.com>