Incorporate patched from casey

This makes it work with older versions of cmake and
inherits the build examples value from the parent

CMake/vtkAndroid.cmake

@@ -61,7 +61,7 @@ macro(compile_vtk_tools)
     PREFIX ${PREFIX_DIR}/vtk-compile-tools
     BINARY_DIR ${BUILD_DIR}/vtk-compile-tools
     ${VTK_BUILD_COMMAND} vtkCompileTools
-    BUILD_ALWAYS 1
+    ${BUILD_ALWAYS_STRING}
     INSTALL_DIR ${INSTALL_DIR}/vtk-compile-tools
     CMAKE_CACHE_ARGS
       -DCMAKE_BUILD_TYPE:STRING=Release
@@ -97,7 +97,7 @@ set(android_cmake_flags
   -DANT_EXECUTABLE:FILE=${ANT_EXECUTABLE}
   -DBUILD_SHARED_LIBS:BOOL=OFF
   -DBUILD_TESTING:BOOL=OFF
-  -DBUILD_EXAMPLES:BOOL=ON
+  -DBUILD_EXAMPLES:BOOL=${BUILD_EXAMPLES}
   -DVTK_RENDERING_BACKEND:STRING=OpenGL2
   -DOPENGL_ES_VERSION:STRING=${OPENGL_ES_VERSION}
   -DVTK_Group_Rendering:BOOL=OFF
@@ -124,6 +124,10 @@ set(android_cmake_flags
   -DModule_vtkRenderingFreeType:BOOL=OFF
 )
 
+set(BUILD_ALWAYS_STRING)
+if(${CMAKE_VERSION} GREATER 3.0)
+  set(BUILD_ALWAYS_STRING "BUILD_ALWAYS 1")
+endif()
 
 macro(crosscompile target toolchain_file)
   ExternalProject_Add(
@@ -133,7 +137,7 @@ macro(crosscompile target toolchain_file)
     BINARY_DIR ${BUILD_DIR}/${target}
     INSTALL_DIR ${INSTALL_DIR}/${target}
     DEPENDS vtk-compile-tools
-    BUILD_ALWAYS 1
+    ${BUILD_ALWAYS_STRING}
     CMAKE_ARGS
       -DCMAKE_INSTALL_PREFIX:PATH=${INSTALL_DIR}/${target}
       -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}