Drop unneeded RELEASE_PLATFORM_VERSION value files

This is automatically set for release configs that match
"^[a-z][a-z][0-9][0-9a-z]$"

Bug: None
Test: manually confirmed no change in flag value
Ignore-AOSP-First: internal process
Change-Id: I712d04ce7c4688c35ef857f626604fc918311fa7
1 file changed