InCallUI: Keep InCallUI in memory (1/3)

In lower end devices, startup of the InCallUI process can take
up to 10 seconds when the device is busy, which prevents the user
from taking the call. Keep the process in memory like previous
versions where they are a part of Phone.apk.

This converts InCallUI into a dummy apk with the persistent
attribute set to true and allows the activity from Dialer.apk,
which uses the com.android.incallui process to be loaded into the
persistent process.

Change-Id: Idfb7fa760eacc8d6e46d50ce682fb06c0acfc8f4
InCallUI: Fix build error

Not including any resource means that the framework-res dependency
is not noted in the build system and sometimes (depending on the
timing) leads to build errors such as

http://jenkins.cyanogenmod.org/job/submission-test/7843/consoleText

Avoid the error by linking against a historical SDK and thus not
depending on framework-res.

Change-Id: I99b2ded018e0b0858bc1c3e31d236fc51d3eec2e