Add precise disconnect cause to CS call metrics

Precise Disconnect cause gives more visibility to the
exact cause of call failures

Bug: 120729393
Test: Manually made CS calls and checked the dumpsys to ensure the
      precise disconnect cause is populated properly

Change-Id: I9cbc3661986db66f4285544354b6ba8d43aa8707
Merged-In: I9cbc3661986db66f4285544354b6ba8d43aa8707