Fix Protobuf importing issue for embedded Python

As I mentioned in b/79751992 #4, when launcher loads __main__ as entry point,
the module dict got set using absolute pkg path which
was runfiles.google.protobuf which caused the type checking failed
(expected: google.protobuf for type()). After then, starting with non entrypoint
python files, the importing module dict would be set with from...import...

So remove dir:runfiles/ from zip section so that during entrypoint Python file
importing the proto files using
from...import..., the type checking can be passed.

Bug: b/79751992
Test: m clean && m out/host/linux-x86/bin/perf_proto_stack;
And execute it:
usage: perf_proto_stack [-h] [--syms SYMS] [--json-out JSON_OUT]
                        [--print-samples] [--skip-kernel-syms]
                        [--print-pid-histogram] [--print-sym-histogram]
                        [--print-dso-histogram] [--parallel PARALLEL]
                        file [file ...]
perf_proto_stack: error: too few arguments

Change-Id: I95a4a9ee95ce7f90d893ea0529c384d7b944abe4
diff --git a/python/python.go b/python/python.go
index a277988..65e3efd 100644
--- a/python/python.go
+++ b/python/python.go
@@ -420,16 +420,20 @@
 			// pkg_path starts from "internal/" implicitly.
 			pkgPath = filepath.Join(internal, pkgPath)
 		} else {
-			// pkg_path starts from "runfiles/" implicitly.
-			pkgPath = filepath.Join(runFiles, pkgPath)
+			if !p.isEmbeddedLauncherEnabled(p.properties.Actual_version) {
+				// pkg_path starts from "runfiles/" implicitly.
+				pkgPath = filepath.Join(runFiles, pkgPath)
+			}
 		}
 	} else {
 		if p.properties.Is_internal != nil && *p.properties.Is_internal {
 			// pkg_path starts from "runfiles/" implicitly.
 			pkgPath = internal
 		} else {
-			// pkg_path starts from "runfiles/" implicitly.
-			pkgPath = runFiles
+			if !p.isEmbeddedLauncherEnabled(p.properties.Actual_version) {
+				// pkg_path starts from "runfiles/" implicitly.
+				pkgPath = runFiles
+			}
 		}
 	}
 
@@ -520,7 +524,9 @@
 		sort.Strings(keys)
 
 		parArgs := []string{}
-		parArgs = append(parArgs, `-P `+pkgPath)
+		if pkgPath != "" {
+			parArgs = append(parArgs, `-P `+pkgPath)
+		}
 		implicits := android.Paths{}
 		for _, k := range keys {
 			parArgs = append(parArgs, `-C `+k)