Prefer single-quoted (non-interpolated) strings where sufficient

com.ibm.wala.cast.java.test.data/build.gradle

@@ -12,7 +12,7 @@ def versionedArchive = 'ajaxslt-0.8.1'
 def packedArchive = "${versionedArchive}.tar.gz"
 
 task downloadJLex(type: Download) {
-	src "http://www.cs.princeton.edu/~appel/modern/java/JLex/current/Main.java"
+	src 'http://www.cs.princeton.edu/~appel/modern/java/JLex/current/Main.java'
 	dest 'src/JLex/Main.java'
 	overwrite false
 }

com.ibm.wala.cast.test/build.gradle

@@ -92,5 +92,5 @@ model {
 
 test {
 	// TODO: compute path on following line from 'xlator_test' library properties somehow
-	systemProperty "java.library.path", "$buildDir/libs/xlator_test/shared"
+	systemProperty 'java.library.path', "$buildDir/libs/xlator_test/shared"
 }