libprocessgroup: Rename files a_cgroup_controller.cpp, a_cgroup_file.cpp

These are for ACgroupController and ACgroupFile, but share a filename
with libcgrouprc_format's CgroupController which can be confusing.

Bug: 349105928
Test: m
Change-Id: Idb270068169b71b0a33101407ddbb5a38cc8d469
diff --git a/libprocessgroup/cgrouprc/Android.bp b/libprocessgroup/cgrouprc/Android.bp
index 7522cfe..cb91247 100644
--- a/libprocessgroup/cgrouprc/Android.bp
+++ b/libprocessgroup/cgrouprc/Android.bp
@@ -32,8 +32,8 @@
         symbol_file: "libcgrouprc.map.txt",
     },
     srcs: [
-        "cgroup_controller.cpp",
-        "cgroup_file.cpp",
+        "a_cgroup_controller.cpp",
+        "a_cgroup_file.cpp",
     ],
     cflags: [
         "-Wall",
diff --git a/libprocessgroup/cgrouprc/cgroup_controller.cpp b/libprocessgroup/cgrouprc/a_cgroup_controller.cpp
similarity index 100%
rename from libprocessgroup/cgrouprc/cgroup_controller.cpp
rename to libprocessgroup/cgrouprc/a_cgroup_controller.cpp
diff --git a/libprocessgroup/cgrouprc/cgroup_file.cpp b/libprocessgroup/cgrouprc/a_cgroup_file.cpp
similarity index 100%
rename from libprocessgroup/cgrouprc/cgroup_file.cpp
rename to libprocessgroup/cgrouprc/a_cgroup_file.cpp