Parcelable: Allow custom describeContents() implementation

plugins/android-extensions/android-extensions-compiler/testData/parcel/codegen/customDescribeContents.kt

@@ -0,0 +1,9 @@
+// CURIOUS_ABOUT describeContents
+
+import kotlinx.android.parcel.*
+import android.os.Parcelable
+
+@MagicParcel
+class User(val firstName: String, val lastName: String, val age: Int, val isProUser: Boolean) : Parcelable {
+    override fun describeContents() = 100
+}

plugins/android-extensions/android-extensions-compiler/testData/parcel/codegen/customDescribeContents.txt

@@ -0,0 +1,41 @@
+public static class User$CREATOR : java/lang/Object, android/os/Parcelable$Creator {
+    public void <init>()
+
+    public final User createFromParcel(android.os.Parcel p0)
+
+    public final User[] newArray(int p0)
+}
+
+public final class User : java/lang/Object, android/os/Parcelable {
+    public final static User$CREATOR CREATOR
+
+    private final int age
+
+    private final java.lang.String firstName
+
+    private final boolean isProUser
+
+    private final java.lang.String lastName
+
+    static void <clinit>()
+
+    public void <init>(java.lang.String p0, java.lang.String p1, int p2, boolean p3)
+
+    public int describeContents() {
+        LABEL (L0)
+        LINENUMBER (8)
+          BIPUSH (100)
+          IRETURN
+        LABEL (L1)
+    }
+
+    public final int getAge()
+
+    public final java.lang.String getFirstName()
+
+    public final java.lang.String getLastName()
+
+    public final boolean isProUser()
+
+    public final void writeToParcel(android.os.Parcel p0, int p1)
+}

plugins/android-extensions/android-extensions-compiler/testData/parcel/codegen/simple.kt

@@ -1,4 +1,4 @@
-// CURIOUS_ABOUT writeToParcel, createFromParcel, <clinit>
+// CURIOUS_ABOUT writeToParcel, createFromParcel, <clinit>, describeContents
 
 import kotlinx.android.parcel.*
 import android.os.Parcelable

plugins/android-extensions/android-extensions-compiler/testData/parcel/codegen/simple.txt

@@ -45,7 +45,12 @@ public final class User : java/lang/Object, android/os/Parcelable {
 
     public void <init>(java.lang.String p0, java.lang.String p1, int p2, boolean p3)
 
-    public final int describeContents()
+    public final int describeContents() {
+        LABEL (L0)
+          LDC (0)
+          IRETURN
+        LABEL (L1)
+    }
 
     public final int getAge()