configs: Add built-in mic to primary input sources

Built-in Mic is the fallback input source if A2dp,SCO,wired
headset,usb headset/device are not connected. During the transient
period between an output device and input device connection, if
primary input profile is selected and none of the above devices
are available, APM selects built-in mic as the new device.
Current configuration does not support built-in mic in mix routes
for primary input resulting in premature input close. This leads
to AudioRecord track recreation. Timing issues have been observed
due to incorrect input attributes being set leading to start record
failures. One such case is device switch (handset to headset)during
incall record. Add built-in mic to avoid timing issues relating to
restoreRecord_l call flow.

CRs-Fixed: 2066905
Change-Id: I97cc5370a843ddfd14f3b43ba4435c2930b8e19a