Android: Add placeholders for platform-specific initialization

Add infrastructure modules to be loaded when initializing builds
targeting Android platforms.

Modules/Platform/Android-Determine.cmake

+#=============================================================================
+# Copyright 2015-2016 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+# When CMAKE_SYSTEM_NAME is "Android", CMakeDetermineSystem loads this module.

Modules/Platform/Android-Initialize.cmake

+#=============================================================================
+# Copyright 2015-2016 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+# When CMAKE_SYSTEM_NAME is "Android", CMakeSystemSpecificInitialize loads this
+# module.