Add 5.15 to the current compatibility matrix

Allow devices built with minlts 5.15.0 to be assigned to the current
compatiblity checks.

Change-Id: I6be6334c6ee4feac637384bfa808f1fc57facd47
diff --git a/compatibility_matrices/Android.bp b/compatibility_matrices/Android.bp
index a59be21..193fd2b 100644
--- a/compatibility_matrices/Android.bp
+++ b/compatibility_matrices/Android.bp
@@ -81,5 +81,6 @@
     ],
     kernel_configs: [
         "kernel_config_current_5.10",
+        "kernel_config_current_5.15",
     ],
 }