Flowerbed sound events are named pink petals

Despite the pink petals-related sound events now encompassing the newly-added wildflowers flowerbed block, the sound events remain with the same ID. For consistency, I would expect these sound events to follow the block.flower_bed.* pattern rather than block.pink_petals.*.

Relates to MC-279995, MC-280079

Steps to reproduce

1. Run /playsound minecraft:block.pink_petals.step
2. Observe that running /playsound minecraft:block.wildflowers.step does not have a sound