Update 3rd-party libraries used by RocksJava (facebook#6084)

Summary:
* LZ4 1.8.3 -> 1.9.2
* ZSTD 1.4.0 -> 1.4.4
Pull Request resolved: facebook#6084

Differential Revision: D18710224

fbshipit-source-id: a461ef19a473d3480acdc027f627ec3048730692

Makefile

@@ -1742,11 +1742,11 @@ BZIP2_DOWNLOAD_BASE ?= https://downloads.sourceforge.net/project/bzip2
 SNAPPY_VER ?= 1.1.7
 SNAPPY_SHA256 ?= 3dfa02e873ff51a11ee02b9ca391807f0c8ea0529a4924afa645fbf97163f9d4
 SNAPPY_DOWNLOAD_BASE ?= https://github.com/google/snappy/archive
-LZ4_VER ?= 1.8.3
-LZ4_SHA256 ?= 33af5936ac06536805f9745e0b6d61da606a1f8b4cc5c04dd3cbaca3b9b4fc43
+LZ4_VER ?= 1.9.2
+LZ4_SHA256 ?= 658ba6191fa44c92280d4aa2c271b0f4fbc0e34d249578dd05e50e76d0e5efcc
 LZ4_DOWNLOAD_BASE ?= https://github.com/lz4/lz4/archive
-ZSTD_VER ?= 1.4.0
-ZSTD_SHA256 ?= 63be339137d2b683c6d19a9e34f4fb684790e864fee13c7dd40e197a64c705c1
+ZSTD_VER ?= 1.4.4
+ZSTD_SHA256 ?= a364f5162c7d1a455cc915e8e3cf5f4bd8b75d09bc0f53965b0c9ca1383c52c8
 ZSTD_DOWNLOAD_BASE ?= https://github.com/facebook/zstd/archive
 CURL_SSL_OPTS ?= --tlsv1