Update Font_Builder_Delegate after commit ee4b6d8

Change Ifaaa58dd alters the way font file resources are loaded. It does
not go through FontFamily.addFontFromAssetManager anymore, but it now
uses Font$Builder.nGetNativeAsset and nGetAssetBuffer. This implements
delegates for those methods.

Bug: 74062470
Test: layoutlib tests
Change-Id: Ia4e499d003c0b23be3dd99092c0c7e0293b0e8c5