Rename ApexName to ApexVariationName

In preparation for reusing the same variation for multiple apexes,
rename ApexName to ApexVariationName.

Bug: 164216768
Test: all soong tests
Change-Id: I88f2c5b192ffa27acd38e01952d0cefd413222a0
diff --git a/apex/apex.go b/apex/apex.go
index 9905b79..2d64815 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -687,9 +687,9 @@
 		return
 	}
 	apexInfo := android.ApexInfo{
-		ApexName:      mctx.ModuleName(),
-		MinSdkVersion: a.minSdkVersion(mctx),
-		Updatable:     a.Updatable(),
+		ApexVariationName: mctx.ModuleName(),
+		MinSdkVersion:     a.minSdkVersion(mctx),
+		Updatable:         a.Updatable(),
 	}
 
 	useVndk := a.SocSpecific() || a.DeviceSpecific() || (a.ProductSpecific() && mctx.Config().EnforceProductPartitionInterface())
@@ -1798,7 +1798,7 @@
 		}
 
 		// Check for the indirect dependencies if it is considered as part of the APEX
-		if am.ApexName() != "" {
+		if am.ApexVariationName() != "" {
 			return do(ctx, parent, am, false /* externalDep */)
 		}