Work-around paletted image decoding bug in SDK_JELLYBEAN

Because there is a bug decoding paletted images in SDK_JELLYBEAN,
we need to avoid encoding paletted images for apps that support
SDK_JELLYBEAN and earlier.

BUG=27643907

Change-Id: Ib7d51ed87435cd36507915d62b0057c06f18b2b6
diff --git a/tools/aapt/Bundle.h b/tools/aapt/Bundle.h
index c449550..ca06ac4 100644
--- a/tools/aapt/Bundle.h
+++ b/tools/aapt/Bundle.h
@@ -249,7 +249,7 @@
      * above. SDK levels that have a non-numeric identifier are assumed
      * to be newer than any SDK level that has a number designated.
      */
-    bool isMinSdkAtLeast(int desired) {
+    bool isMinSdkAtLeast(int desired) const {
         /* If the application specifies a minSdkVersion in the manifest
          * then use that. Otherwise, check what the user specified on
          * the command line. If neither, it's not available since