fix(build): add missing gates for cross-compile and Android
drm_mode_matching.cpp: add for size_t (splash sub-build on K1/K2 uses stricter include paths).
bt_print_utils.cpp: gate with HELIX_HAS_LABEL_PRINTER to match sibling bt printer sources; Android build defines no label printer support and was failing to link LabelPrinterSettingsManager symbols.