Fix cmake 3.18 build error (#114)

Author: Kudo

android/CMakeLists.txt

@@ -7,6 +7,7 @@
 #
 
 cmake_minimum_required(VERSION 3.5.1)
+project(react-native-v8)
 
 set(CMAKE_VERBOSE_MAKEFILE ON)
 set(CMAKE_CXX_STANDARD 14)

android/build.gradle

@@ -156,8 +156,7 @@ android {
                   "-DBOOST_VERSION=${BOOST_VERSION}",
                   "-DBUILD_DIR=${buildDir}",
                   "-DRN_DIR=${reactNativeDir}",
-                  "-DV8_ANDROID_DIR=${v8AndroidDir}",
-                  "--clean-first"
+                  "-DV8_ANDROID_DIR=${v8AndroidDir}"
         abiFilters (*reactNativeArchitectures())
         _stackProtectorFlag ? (cppFlags("-fstack-protector-all")) : null
       }