Fix DynamicLayout last line spacing

StaticLayout did not work as expected when there is a line ending with
'\n'. For those cases it would calculate 2 lines, but would
discard line spacing for both of them. This CL fixed that issue. Also
DynamicLayout asks StaticLayout not to add line spacing for the last
line of the text.

Test: Manual/Visual test
Test: bit -t FrameworksCoreTests:android.text.StaticLayoutTest
Test: bit -t FrameworksCoreTests:android.text.StaticLayoutTextMeasuringTest
Test: bit -t FrameworksCoreTests:android.text.StaticLayoutLineBreakingTest
Test: bit -t FrameworksCoreTests:android.text.DynamicLayoutTest
Test: bit -t FrameworksCoreTests:android.text.DynamicLayoutBlocksTest
Test: bit -t FrameworksCoreTests:android.widget.TextViewTest
Test: bit -t FrameworksCoreTests:android.widget.EditorCursorTest
Test: bit -t CtsTextTestCases:android.text.cts.StaticLayoutTest
Test: bit -t CtsTextTestCases:android.text.cts.DynamicLayoutTest
Test: bit -t CtsWidgetTestCases:android.widget.cts.TextViewTest
Test: bit -t CtsWidgetTestCases:android.widget.cts.EditTextTest

Bug: 25194907
Change-Id: I0d901ecf768b25faea156b73097541da4b93d6d0