Disable source map id usage in eng builds

Injecting the source map details into stack frames for eng builds
adds unnecessary noise, as the `--debug` configuration implicitly
disables optimization/obfuscation.

Bug: 377957431
Test: lunch eng target + m + ensure no --source-file-template in R8 args
Change-Id: I28235f148d311d3422c5d0f9dda178d5984e6e30