Drop lc_cache to 15gb as we don't use it as much anymore

Test: presubmit
Bug: 279124940
Change-Id: I230cbdcf675e13ef5bef5464e34623b59b1b4f81
diff --git a/global_configuration/com/android/tradefed/host/HostOptions.java b/global_configuration/com/android/tradefed/host/HostOptions.java
index c33424c..49586b7 100644
--- a/global_configuration/com/android/tradefed/host/HostOptions.java
+++ b/global_configuration/com/android/tradefed/host/HostOptions.java
@@ -143,8 +143,8 @@
     @Option(
             name = "cache-size-limit",
             description =
-                    "The maximum allowed size(bytes) of the local file cache. (default: 20GB)")
-    private Long mCacheSizeLimit = 20L * 1024L * 1024L * 1024L;
+                    "The maximum allowed size(bytes) of the local file cache. (default: 15GB)")
+    private Long mCacheSizeLimit = 15L * 1024L * 1024L * 1024L;
 
     @Option(
             name = "test-phase-timeout",