Android: use Upper function for Unicode string

[developernotes]

Hello @alisichkin

SQLCipher for Android removed ICU support in the 3.5 series release for support on Android 7:

SQLCipher for Android Release—Android N Support

We are happy to announce the release of SQLCipher for Android 3.5.1. This is an urgent and mandatory upgrade for applications wishing to support Android N when it is publicly released. This release of SQLCipher for Android incorporates several major changes to facilitate operating on Android 2.1 through Android N, supporting armeabi, armeabi-v7a, and x86 platforms. The Google Android team contacted us directly, requesting many of the changes below. These changes were mandatory to make SQLCipher…

Adding support for ICU to the library would require a custom build and/or extension to the library.