Disable hiddenapi check for building from prebuilts.

Add ReleaseDefaultModuleBuildFromSource to config.productVariables and
use this parameter to disable hiddenapi check.

Test: DEFAULT_MODULE_BUILD_FROM_SOURCE=false m (not failing hiddenapi
check after disabling)
Bug: 301871981
Change-Id: I86b3f3bc21d546022a503a1c6a8a641d4e785565
diff --git a/android/variable.go b/android/variable.go
index d33294c..79f585e 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -481,6 +481,8 @@
 
 	ReleaseAconfigFlagDefaultPermission string `json:",omitempty"`
 
+	ReleaseDefaultModuleBuildFromSource *bool `json:",omitempty"`
+
 	KeepVndk *bool `json:",omitempty"`
 
 	CheckVendorSeappViolations *bool `json:",omitempty"`