compress envelopes with lz4

Cargo.lock

@@ -3167,6 +3167,12 @@ dependencies = [
  "linked-hash-map",
 ]
 
+[[package]]
+name = "lz4_flex"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ea9b256699eda7b0387ffbc776dd625e28bde3918446381781245b7a50349d8"
+
 [[package]]
 name = "malloc_buf"
 version = "0.0.6"
@@ -6414,6 +6420,7 @@ dependencies = [
  "keyvaluedb-web",
  "lazy_static",
  "libc",
+ "lz4_flex",
  "ndk",
  "ndk-glue",
  "netlink-packet-route 0.15.0",