Drop obsolete cf_local_image target

This is no longer required as the extra targets we need were already
added to droidcore (use of "make dist" is also unnecessary unless you
want to generate OTA packages.)

Bug: 113175337
Change-Id: I8fd1deb47c5d2c80265dbedc20622668504ba531
Merged-In: I8fd1deb47c5d2c80265dbedc20622668504ba531
Signed-off-by: Alistair Strachan <astrachan@google.com>