Fix layoutlib build.

Was using private data structures from libcore.

Change-Id: I5bd43190081891659e18b5c871686e6078efcc81
diff --git a/tools/layoutlib/bridge/src/libcore/icu/ICU_Delegate.java b/tools/layoutlib/bridge/src/libcore/icu/ICU_Delegate.java
index d40352f..998b08b 100644
--- a/tools/layoutlib/bridge/src/libcore/icu/ICU_Delegate.java
+++ b/tools/layoutlib/bridge/src/libcore/icu/ICU_Delegate.java
@@ -231,7 +231,7 @@
         result.percent = '%';
         result.perMill = '\u2030';
         result.monetarySeparator = ' ';
-        result.minusSign = '-';
+        result.minusSign = "-";
         result.exponentSeparator = "e";
         result.infinity = "\u221E";
         result.NaN = "NaN";