configs: sdm660: Remove Dolby formats by default

AC3, EAC3 formats are supported only when license and
respective decoders are present. Having these entries
in policy configuration by default will unnecessarily
trigger open_output_stream and then fail when decoders
are not present. This results in glitches at the
begining of playback of video clips with AC3 or
EAC3 audio contents.

Removed these entries to make the video playbck smooth
with out any glitches.

CRs-Fixed: 2200436
Change-Id: Ie8ad6faaf3149b916db77b2246e985fb859a23ab