example/ivy/android: use monospace & pre-wrap for WebView text formatting

Output from ivy is carefully formatted to work best in terminal.
Use of monospace & pre-wrap white space make table-format output look nicer.

Change-Id: If11fd57c8e685c01825fb1c2dd8b6d24fe860850
Reviewed-on: https://go-review.googlesource.com/c/mobile/+/356730
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Hajime Hoshi <hajimehoshi@gmail.com>
Trust: Peter Weinberger <pjw@google.com>
diff --git a/example/ivy/android/app/src/main/assets/tape.html b/example/ivy/android/app/src/main/assets/tape.html
index 4859f38..c88ffac 100644
--- a/example/ivy/android/app/src/main/assets/tape.html
+++ b/example/ivy/android/app/src/main/assets/tape.html
@@ -5,27 +5,28 @@
 -->
 <html>
 <head>
-    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no" charset="UTF-8">
     <style>
         body {
             font-family: sans-serif;
         }
-
         div {
             padding: 1;
+            white-space: pre-wrap;
+            font-family: "Roboto Mono", monospace;
         }
-
         .comment {
             color: grey;
         }
-
+        .expr {
+            font-weight: bold;
+        }
         .flow-hide {
             text-overflow: ellipsis;
             word-break: break-all;
             white-space: nowrap;
             overflow: hidden;
         }
-
         .flow-show {
             word-break: break-all;
         }
@@ -44,7 +45,7 @@
     if (tag == "comment") {
         el.classList.add("comment");
     } else if (tag == "expr") {
-
+        el.classList.add("expr");
     } else {
         el.classList.add("flow-show");
         el.onclick = function() {