Improve bazel action status mnemonics

Example output line:

```
CppCompile: [bazel-out/android_arm-fastbuild-ST-dd3fdd7bf572/bin/bionic/libc/_objs/libc_bionic_asm/
0/strcpy.o]
```

Instead of just `CppCompile`.

Fixes: 220234318
Test: `m libc` in mixed builds
Change-Id: I3e079006b1f1bb9e8db5b4f022ea993d7693aeb5