Add Super_image_in_update_package prop to super_image

This property will be used to generate misc_info.txt

Test: compared misc_info.txt of soong and make super.img
Bug: 399788100
Change-Id: I1354dffb37688414c2ecad22fcbde05fe08383e8
diff --git a/android/variable.go b/android/variable.go
index 81999f3..7ac9f08 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -667,6 +667,7 @@
 	AbOtaPartitions                   []string                                 `json:",omitempty"`
 	AbOtaKeys                         []string                                 `json:",omitempty"`
 	AbOtaPostInstallConfig            []string                                 `json:",omitempty"`
+	BoardSuperImageInUpdatePackage    bool                                     `json:",omitempty"`
 
 	// Avb (android verified boot) stuff
 	BoardAvbEnable          bool                                `json:",omitempty"`