Upgrade to android13-5.15 kernel

... in preparation for the migration to android14-5.15 kernel.

In addition, drop the version suffix from the module names to make
version upgrade less intrusive.

Bug: 233317671
Test: watch TH
Change-Id: Id1fe79c848c5ecb9c3ff5c0ba2c2527e7d907d0e
diff --git a/tests/Android.bp b/tests/Android.bp
index 2c36a62..a06a33a 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -16,7 +16,7 @@
     default_applicable_licenses: ["Android-Apache-2.0"],
 }
 
-kernel_version = "5.10"
+kernel_version = "5.15"
 
 kernel_stem = "kernel_prebuilts-" + kernel_version