android: Add Android and C++ support to a couple files

These are needed downstream in VulkanTools for Android support.
diff --git a/vk_helper.py b/vk_helper.py
index 5a36fbb..bb0ee82 100755
--- a/vk_helper.py
+++ b/vk_helper.py
@@ -579,6 +579,7 @@
         self.size_helper_gen.setCopyright(self._generateCopyright())
         self.size_helper_gen.setHeader(self._generateSizeHelperHeader())
         self.size_helper_gen.setBody(self._generateSizeHelperFunctions())
+        self.size_helper_gen.setFooter(self._generateSizeHelperFooter())
         self.size_helper_gen.generate()
 
     def generateSizeHelperC(self):
@@ -1482,6 +1483,10 @@
 
     def _generateSizeHelperHeader(self):
         header = []
+        header.append('\n#ifdef __cplusplus\n')
+        header.append('extern "C" {\n')
+        header.append('#endif\n')
+        header.append("\n")
         header.append("//#includes, #defines, globals and such...\n")
         for f in self.include_headers:
             header.append("#include <%s>\n" % f)
@@ -1498,6 +1503,12 @@
         header.append('\n// Function definitions\n')
         return "\n".join(header)
 
+    def _generateSizeHelperFooter(self):
+        footer = []
+        footer.append('\n\n#ifdef __cplusplus')
+        footer.append('}')
+        footer.append('#endif')
+        return "\n".join(footer)
 
     def _generateHeader(self):
         header = []