Remove host_snapshot module

Remove host_snapshot implementation which is no longer in use.

Bug: 332986564
Test: soong build succeeded
Change-Id: I96ee4eb319f380d9f85de7f9716e63513838624c

snapshot/Android.bp

@@ -14,12 +14,8 @@ bootstrap_go_package {
     // Source file name convention is to include _snapshot as a
     // file suffix for files that are generating snapshots.
     srcs: [
-        "host_snapshot.go",
         "snapshot_base.go",
         "util.go",
     ],
-    testSrcs: [
-        "host_test.go",
-    ],
     pluginFor: ["soong_build"],
 }