Remove unused leading_zero_possible field (#2821)

Remove unused leading_zero_possible field from phonemetadata.proto

Deleted all methods that refer to this.
Regenerated jars - because we no longer write a boolean for the removed proto field, all the java metadata files needed regenerating too.

java/libphonenumber/src/com/google/i18n/phonenumbers/Phonemetadata.java

@@ -828,22 +828,6 @@ public final class Phonemetadata {
       return this;
     }
 
-    // optional bool leading_zero_possible = 26 [default = false];
-    private boolean hasLeadingZeroPossible;
-    private boolean leadingZeroPossible_ = false;
-    public boolean hasLeadingZeroPossible() { return hasLeadingZeroPossible; }
-    public boolean isLeadingZeroPossible() { return leadingZeroPossible_; }
-    public PhoneMetadata setLeadingZeroPossible(boolean value) {
-      hasLeadingZeroPossible = true;
-      leadingZeroPossible_ = value;
-      return this;
-    }
-    public PhoneMetadata clearLeadingZeroPossible() {
-      hasLeadingZeroPossible = false;
-      leadingZeroPossible_ = false;
-      return this;
-    }
-
     // optional bool mobile_number_portable_region = 32 [default = false];
     private boolean hasMobileNumberPortableRegion;
     private boolean mobileNumberPortableRegion_ = false;
@@ -982,8 +966,6 @@ public final class Phonemetadata {
         objectOutput.writeUTF(leadingDigits_);
       }
 
-      objectOutput.writeBoolean(leadingZeroPossible_);
-
       objectOutput.writeBoolean(mobileNumberPortableRegion_);
     }
 
@@ -1143,8 +1125,6 @@ public final class Phonemetadata {
         setLeadingDigits(objectInput.readUTF());
       }
 
-      setLeadingZeroPossible(objectInput.readBoolean());
-
       setMobileNumberPortableRegion(objectInput.readBoolean());
     }
   }