restore device/generic/common

Change-Id: I3b9a91816f61ffb7a92d5658c5ad484e7ab21f76

remove.xml

@@ -20,7 +20,6 @@
   <remove-project name="device/generic/arm64" />
   <remove-project name="device/generic/armv7-a-neon" />
   <remove-project name="device/generic/car" />
-  <remove-project name="device/generic/common" />
   <remove-project name="device/generic/goldfish" />
   <remove-project name="device/generic/goldfish-opengl" />
   <remove-project name="device/generic/mips" />