deps: drop snappy

librime doesn't enable any compression for leveldb, and snappy is also not necessary on Android, so let us drop it.
This may decrease app size significantly.

Author: WhiredPlanck

.gitmodules

@@ -5,9 +5,6 @@
 [submodule "OpenCC"]
 	path = app/src/main/jni/OpenCC
 	url = https://github.com/BYVoid/OpenCC.git
-[submodule "snappy"]
-	path = app/src/main/jni/snappy
-	url = https://github.com/google/snappy.git
 [submodule "librime"]
 	path = app/src/main/jni/librime
 	url = https://github.com/rime/librime.git

app/src/main/jni/CMakeLists.txt

@@ -32,13 +32,6 @@ option(YAML_CPP_BUILD_TESTS "" OFF)
 option(YAML_CPP_INSTALL "" OFF)
 add_subdirectory(librime/deps/yaml-cpp)
 
-# enable compress for leveldb
-option(SNAPPY_BUILD_TESTS "" OFF)
-option(SNAPPY_BUILD_BENCHMARKS "" OFF)
-option(SNAPPY_INSTALL "" OFF)
-add_subdirectory(snappy)
-
-set(HAVE_SNAPPY TRUE)
 option(LEVELDB_BUILD_TESTS "" OFF)
 option(LEVELDB_BUILD_BENCHMARKS "" OFF)
 option(LEVELDB_INSTALL "" OFF)