Convert String8 to std::string

String8 is deprecated.

Test: m -j and uncomment DEBUG flags
in VelocityTracker to view coordinates
in logcat.

Change-Id: I968685765f06418be73fbb8ad2747a1fe8ed324e
diff --git a/libs/input/Android.bp b/libs/input/Android.bp
index 9294419..2f39976 100644
--- a/libs/input/Android.bp
+++ b/libs/input/Android.bp
@@ -34,6 +34,7 @@
     clang: true,
 
     shared_libs: [
+        "libbase",
         "liblog",
         "libcutils",
     ],