Cache the layout result if the font feature is specified

Before this patch, the layout is not cahced if the font feature settings
are specified. This CL caches the layout even if the font feature is
specifid.

This is necessary because the Java layer will use font feature settings
for disabling ligature if the inter word justification is specified.

Bug: 283193133
Test: minikin_tests
Change-Id: If54c448d3f496b3323e2d3177803b815f433b65c
17 files changed