I can confirm that placing the pumpkin on the ground then using the shears to change it to a carved pumpkin does work in the Minecraft for Android. I was able to successfully get the achievement this way a few hours ago. However, I have done the same thing dozens of times in Minecraft Windows 10 and Minecraft playing on Xbox One without getting the achievement.
As a side note, I did get the achievement by doing this in Minecraft Xbox One edition on July 31st. So while it is possible to get the achievement, it seems to be glitched to the point where it may not work at all.
I should add that I got the Achievement on Minecraft for Android while playing "Minecraft for Android" in Beta. I neglected to mention this when I initially posted.
K. A. Romeo
I can confirm that placing the pumpkin on the ground then using the shears to change it to a carved pumpkin does work in the Minecraft for Android. I was able to successfully get the achievement this way a few hours ago. However, I have done the same thing dozens of times in Minecraft Windows 10 and Minecraft playing on Xbox One without getting the achievement.
As a side note, I did get the achievement by doing this in Minecraft Xbox One edition on July 31st. So while it is possible to get the achievement, it seems to be glitched to the point where it may not work at all.
I should add that I got the Achievement on Minecraft for Android while playing "Minecraft for Android" in Beta. I neglected to mention this when I initially posted.