Merge changes from topic "prebuilt-hiddenapi"

* changes:
  Supply LOCAL_SOONG_DEX_JAR for java_import with compile_dex.
  Enable an apex to include a java_import.
  Enable prebuilt hiddenapi CSV files.

android/variable.go

@@ -367,6 +367,8 @@ type productVariables struct {
 	BoardKernelModuleInterfaceVersions []string `json:",omitempty"`
 
 	BoardMoveRecoveryResourcesToVendorBoot *bool `json:",omitempty"`
+
+	PrebuiltHiddenApiDir *string `json:",omitempty"`
 }
 
 func boolPtr(v bool) *bool {