[blobfs] Increase chunked compression level.

Value increased from 3->14, which is the smallest value that does not
increase the content or image size for blobfs per the baseline.

This will result in slowdowns on the blob installation path --
compression will be an order of magnitude slower. However, note that
installation is still IO bound even after this change.

Change-Id: Ied2dcfa1388ea0cfae8847baaee21d7c83a095fd
diff --git a/zircon/system/ulib/blobfs/compression/chunked.cc b/zircon/system/ulib/blobfs/compression/chunked.cc
index d1522b8..dc3ead8d 100644
--- a/zircon/system/ulib/blobfs/compression/chunked.cc
+++ b/zircon/system/ulib/blobfs/compression/chunked.cc
@@ -19,7 +19,7 @@
 
 namespace {
 
-constexpr int kDefaultLevel = 3;
+constexpr int kDefaultLevel = 14;
 
 using chunked_compression::Status;
 using chunked_compression::ToZxStatus;