Optional use of UTF-8 strings in resource bundles

Allows the use of UTF-8 for packing resources instead of the
default of UTF-16 for Java. When strings are extracted from the
ResStringPool, they are converted to UTF-16 and the result is
cached for subsequent calls.

When using aapt to package, add in the "-8" switch to pack the
resources using UTF-8. This will result in the value, key, and
type strings as well as the compiled XML string values taking
significantly less space in the final application package in
most scenarios.

Change-Id: I129483f8b3d3b1c5869dced05cb525e494a6c83a
diff --git a/include/utils/String16.h b/include/utils/String16.h
index a2d22ee..07a0c11 100644
--- a/include/utils/String16.h
+++ b/include/utils/String16.h
@@ -49,12 +49,17 @@
 // Version of strzcmp16 for comparing strings in different endianness.
 int strzcmp16_h_n(const char16_t *s1H, size_t n1, const char16_t *s2N, size_t n2);
 
+// Convert UTF-8 to UTF-16 including surrogate pairs
+void utf8_to_utf16(const uint8_t *src, size_t srcLen, char16_t* dst, const size_t dstLen);
+
 }
 
 // ---------------------------------------------------------------------------
 
 namespace android {
 
+// ---------------------------------------------------------------------------
+
 class String8;
 class TextOutput;