Fix package path of android/soong/android pctx

android/soong/common was renamed to android/soong/android long
ago, but the pctx package path was still "android/soong/common".
This required all users of rules defined in android/soong/android
to import "android/soong/android" and then
pctx.Import("android/soong/common").

Test: m checkbuild
Change-Id: I20d096522760538f7cfc2bec3d4bfeba99b275d4
diff --git a/apex/apex.go b/apex/apex.go
index ce1ed46..3327a56 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -119,7 +119,7 @@
 )
 
 func init() {
-	pctx.Import("android/soong/common")
+	pctx.Import("android/soong/android")
 	pctx.Import("android/soong/java")
 	pctx.HostBinToolVariable("apexer", "apexer")
 	// ART minimal builds (using the master-art manifest) do not have the "frameworks/base"