Update expectation for library -assumenosideeffects test

Change-Id: I3869ad3ff16935eb2258d4b1bf2aae91b01caf5f

src/test/java/com/android/tools/r8/shaking/assumenosideeffects/AssumeNoSideEffectsForLibraryMethodTest.java

diff --git a/src/test/java/com/android/tools/r8/shaking/assumenosideeffects/AssumeNoSideEffectsForLibraryMethodTest.java b/src/test/java/com/android/tools/r8/shaking/assumenosideeffects/AssumeNoSideEffectsForLibraryMethodTest.java
index 632863a..1fa9ac6 100644
--- a/src/test/java/com/android/tools/r8/shaking/assumenosideeffects/AssumeNoSideEffectsForLibraryMethodTest.java
+++ b/src/test/java/com/android/tools/r8/shaking/assumenosideeffects/AssumeNoSideEffectsForLibraryMethodTest.java
@@ -36,7 +36,7 @@
     testForR8(parameters.getBackend())
         .addProgramClasses(TestClass.class)
         .addKeepMainRule(TestClass.class)
-        .addKeepRules("-assumenosideeffects class java.lang.Object { int hashCode() return 42; }")
+        .addKeepRules("-assumenosideeffects class java.lang.String { int hashCode() return 42; }")
         .setMinApi(parameters.getApiLevel())
         .compile()
         .inspect(
@@ -58,7 +58,7 @@
   static class TestClass {
 
     public static void main(String[] args) {
-      System.out.println(new Object().hashCode());
+      System.out.println("".hashCode());
     }
   }
 }