[1.9] Renamed walls, slabs and stairs are now longer renamed

Partner Rank: 2

Partner Team Reporting: Noxcrew

Verification builds and Platforms:
ver. 1.9.0.14,rc4 build 1627786, Win10 and Android

Summary:
The new language strings for walls, slabs, and stairs have replaced the old strings, removing backwards compatability.

Impact:
Blocks which were previously renamed are now not properly named. This leads to player confusion and the content looks unprofessional and unpolished.
This will affect any partner who has renamed the blocks

Repro Steps:

1. Download the content "Millionaire Mansions" from the marketplace in 1.9
2. Create a new world and search for the item "Quartz Wall" in your inventory.
3. Observe no block appear
4. Search for a cobblestone wall
5. Observe a quartz wall appears
6. Repeat the test in 1.8
7. Observe the Quartz wall

Observed Results:
The search results are empty as the block is unrenamed

Expected Results:
The item "Quartz Wall" appears in search results.

Screenshots/Videos attached: No

Notes:
This has been introuduced in 1.9. And will likely affect any partner that changed the language string for the walls, slabs, or stairs.

While I understand the new language strings have been introduced for organisation, it would be beneficial to have the item accept either language string, with the old string taking priority. Otherwise a lot of content would need to be fixed and resubmitted.

Old String: tile.cobblestone_wall.mossy.name=
New String: tile.cobblestone_wall.mossy_cobblestone.name=