[Custom Key Glyph] KeyCombination should be parcelable

This CL fixes an issue that if there is hardware-defined-shortcut tag in keyboard-glyph-map xml, it throws exception when calling inputManager.getKeyGlyphMap because KeyCombination is not parcelable.

Bug: 375681062
Test: Manual, tested calling from SystemUI
Flag: com.android.hardware.input.keyboard_glyph_map
Change-Id: I3de7036d84d3ce0eee4212719755bf9ebe19a5b9