Add BoardKernelModuleInterfaceVersions.

This is a list of KMI versions for this board. Only gki_apex modules
with matching kmi_version field is enabled.

Test: build GKI apexes
Bug: 162888350
Change-Id: Ieb2116b79e3985ba15155a3cb8a2c340b46473c7
diff --git a/android/config.go b/android/config.go
index 92a21a7..10a78a5 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1248,6 +1248,10 @@
 	return c.config.productVariables.BoardKernelBinaries
 }
 
+func (c *deviceConfig) BoardKernelModuleInterfaceVersions() []string {
+	return c.config.productVariables.BoardKernelModuleInterfaceVersions
+}
+
 // The ConfiguredJarList struct provides methods for handling a list of (apex, jar) pairs.
 // Such lists are used in the build system for things like bootclasspath jars or system server jars.
 // The apex part is either an apex name, or a special names "platform" or "system_ext". Jar is a