Build flag to runtime check hf indicator

Replace BTA_HF_CLIENT_INDICATOR_SIGNAL_POS with
bluetooth.headsetclient.disable_indicator.position

Bug: 263323082
Bug: 157935962
Bug: 199827901
Test: Manual
Change-Id: Ibb81687841f4689e162f6caf31a38fca06c0ecee
(cherry picked from commit b1fa1a95)
Merged-In: Ibb81687841f4689e162f6caf31a38fca06c0ecee