Update icons in Exchange for consistency

Bug: 5280197
Change-Id: I4db2d68d913747e6206e198cd3f4ca6c991e39d1
diff --git a/res/mipmap-hdpi/icon.png b/res/mipmap-hdpi/icon.png
index b0b3f71..5bdc9d6 100644
--- a/res/mipmap-hdpi/icon.png
+++ b/res/mipmap-hdpi/icon.png
Binary files differ
diff --git a/res/mipmap-mdpi/icon.png b/res/mipmap-mdpi/icon.png
index e874589..eb992dc 100644
--- a/res/mipmap-mdpi/icon.png
+++ b/res/mipmap-mdpi/icon.png
Binary files differ
diff --git a/res/mipmap-xhdpi/icon.png b/res/mipmap-xhdpi/icon.png
new file mode 100644
index 0000000..8f6a216
--- /dev/null
+++ b/res/mipmap-xhdpi/icon.png
Binary files differ