Do not build Gandiva JNI bindings by default

Change-Id: I38ab476a3d44e7f16f6fbe693e0e035503e4510e

.travis.yml

@@ -109,6 +109,7 @@ matrix:
     jdk: openjdk8
     env:
     - ARROW_TRAVIS_GANDIVA=1
+    - ARROW_TRAVIS_GANDIVA_JAVA=1
     - ARROW_TRAVIS_GANDIVA_TESTS=1
     - ARROW_TRAVIS_OPTIONAL_INSTALL=1
     - ARROW_CPP_BUILD_TARGETS="gandiva"
@@ -160,6 +161,7 @@ matrix:
     addons:
     env:
     - ARROW_TRAVIS_GANDIVA=1
+    - ARROW_TRAVIS_GANDIVA_JAVA=1
     - ARROW_TRAVIS_GANDIVA_TESTS=1
     - ARROW_TRAVIS_OPTIONAL_INSTALL=1
     - ARROW_CPP_BUILD_TARGETS="gandiva"

ci/travis_before_script_cpp.sh

@@ -99,6 +99,9 @@ fi
 
 if [ $ARROW_TRAVIS_GANDIVA == "1" ]; then
   CMAKE_COMMON_FLAGS="$CMAKE_COMMON_FLAGS -DARROW_GANDIVA=ON"
+  if [ $ARROW_TRAVIS_GANDIVA_JAVA == "1" ]; then
+      CMAKE_COMMON_FLAGS="$CMAKE_COMMON_FLAGS -DARROW_GANDIVA_JAVA=ON"
+  fi
   if [ $ARROW_TRAVIS_GANDIVA_TESTS == "1" ]; then
     CMAKE_COMMON_FLAGS="$CMAKE_COMMON_FLAGS -DARROW_BUILD_TESTS=ON"
   fi

cpp/CMakeLists.txt

@@ -326,7 +326,7 @@ Always OFF if building binaries"
 
   option(ARROW_GANDIVA_JAVA
     "Build the Gandiva JNI wrappers"
-    ON)
+    OFF)
 endif()
 
 if (ARROW_OPTIONAL_INSTALL)

dev/tasks/gandiva-jars/build-cpp.sh

@@ -27,6 +27,7 @@ pushd arrow/cpp
   pushd build
     cmake -DCMAKE_BUILD_TYPE=Release \
           -DARROW_GANDIVA=ON \
+          -DARROW_GANDIVA_JAVA=ON \
           -DARROW_GANDIVA_STATIC_LIBSTDCPP=ON \
           -DARROW_BUILD_UTILITIES=OFF \
           -DARROW_BOOST_USE_SHARED=OFF \