Make LineBreaker public

This CL includes:
- Move NativeLineBreaker/NativeMeasuredParagraph to android.graphics.text
package since these two uses the shaping result of the text which is a
part of graphics responsibility. At the same time, by this moving,
minikin is only used by android.graphics package.
- Rename NativeLineBreaker/NativeMeasuredParagraph to
LineBreaker/MeasuredText.
- Updated comments of the break strategy and hyphenation frequency.

Bug: 112327179
Test: atest CtsTextTestCases CtsGraphicsTestCases CtsWidgetTestCases
Change-Id: Id69c328e7c9097b9fc11b5c0bd04d1c2e0939c6a