Blocks of diamond and blocks of emerald use "metal" block sounds, despite not being metal blocks

The bug

The placement, breaking, walking on, etc. sounds for minecraft:diamond_block and minecraft:emerald_block are the higher-pitched sounds associated with metal blocks. This does not make much sense, as neither diamond nor emerals are a type of metal; diamond and emerald are types of rock. As a result, it'd be expected that the "stone" sound, rather than the "metal" sound, would be used for diamond blocks and emerald blocks.

This was originally included under MC-91091. However, many of the cases previously included in that ticket have since been split into other tickets and officially fixed (recent examples include MC-182820 and MC-200484), so I'm giving this one a chance on its own as well.

How to reproduce

1. Obtain diamond blocks and/or emerald blocks

2. Place, break, walk on and/or fall on these blocks

Expected results

The "stone" set of block sounds would be used.

Actual results

The "metal" set of blocks sounds are used instead.

How to fix

Fixing this is as simple as changing these blocks from the metal sounds over to the stone sounds (or perhaps giving them their own, new, distinct sounds).