Fix dialer crash after making 4G confernce call with anomaly number

If the number includes character, the characters are removed after
formatting the number so that causes IllegalArgumentException due to
URI without path.

To fix it, if the number or child number is empty, skip querying the
contact info.

Change-Id: Ide5c405bf1d1d61bc5d836f9f6ba4c276b13d908
CRs-Fixed: 2012502
diff --git a/src/com/android/dialer/calllog/ContactInfoHelper.java b/src/com/android/dialer/calllog/ContactInfoHelper.java
index ea39d03..c07ca2a 100644
--- a/src/com/android/dialer/calllog/ContactInfoHelper.java
+++ b/src/com/android/dialer/calllog/ContactInfoHelper.java
@@ -292,10 +292,13 @@
                 }
                 String combName = "";
                 for (String num : nums) {
-                    ContactInfo singleCi = lookupContactFromUri(getContactInfoLookupUri(num),
-                            isSip);
+                    ContactInfo singleCi = null;
+                    if (!TextUtils.isEmpty(num)) {
+                        singleCi = lookupContactFromUri(
+                                getContactInfoLookupUri(num), isSip);
+                    }
                     // If contact does not exist, need to avoid changing static empty-contact.
-                    if (singleCi == ContactInfo.EMPTY) {
+                    if (singleCi == null || singleCi == ContactInfo.EMPTY) {
                         singleCi = new ContactInfo();
                     }
                     if (TextUtils.isEmpty(singleCi.name)) {