Deprecate Snapshot build

Existing snapshot code will no longer work from VNDK deprecation, but it
can give confusion to users if we keep code for the snapshot - and it
adds complexity on existing code while it is not in use. This change
removes all snapshot definition except host snapshot and its usage.

Bug: 330100430
Bug: 332986564
Test: AOSP CF build succeeded
Change-Id: Ieb6fa43d5e38315c662ce997bc305b744b367c24

snapshot/Android.bp

@@ -16,15 +16,11 @@ bootstrap_go_package {
     srcs: [
         "host_fake_snapshot.go",
         "host_snapshot.go",
-        "recovery_snapshot.go",
-        "snapshot.go",
         "snapshot_base.go",
         "util.go",
-        "vendor_snapshot.go",
     ],
     testSrcs: [
         "host_test.go",
-        "test.go",
     ],
     pluginFor: ["soong_build"],
 }