Use custom module for versioned font files

The prebuilt_versioned_font module includes font files based on build
flags. With this custom module, we can refer the build flags directly
instead of propagating buildflags from mk file to bp file with randomly
generated namespaces.

This module has two mandatory properties, versionFlag and
defaultVersion.
The versionFlag is a build flag used for versioning.
The defaultVersion is a default version string used for environment that
does not have build flags, e.g. SDK builds.

For example,

prebuilt_versioned_font {
  name: "NotoSans.ttf",
  versionFlag: "RELEASE_PACKAGE_NOTO_SANS",
  defaultVersion: "1.000",
}

then, if RELEASE_PACKAGE_NOTO_SANS is 2.000, the font file located in

{root}/font/2.000/NotoSans.ttf

is loaded. The directory name and file name can be configured with
optional fontFile property and fontFile property.

Bug: N/A
Test: m and manually confirmed the versioned font files are included.
Merged-In: I2d09de745cb28f50196ffe8857ca9578f2eb6ee1
Change-Id: I2d09de745cb28f50196ffe8857ca9578f2eb6ee1