Use a host java program to generate the background text

This program uses java.awt.Graphics2D to generate the background text
files used under recovery mode. And thus we don't need to do the manual
work by running emulators with different dpi.

The program takes the following parameters:
1. imageWidth: The number of pixels per line; and the text strings will be
   wrapped accordingly.
2. textName: The description of the text string, e.g. "recovery_erasing",
   "recovery_installing_security"
3. fontDirectory: The directory that contains all the support .ttf | .ttc
   files, e.g. $OUT/system/fonts/
4. resourceDirectory: The resource directory that contains all the translated
   strings in xml format, e.g. bootable/recovery/tools/recovery_l10n/res/
5. outputFilename: Path to the generated image.

Bug: 74397117
Test: checks the generated png files
Change-Id: Ia5506a0a4f5da1ebfd7090345eb246f44b265075