feat: add Weight to common types for Shopping APIs to be used for a…

…ccounts bundle

docs: A comment for field `amount_micros` in message `.google.shopping.type.Price` is changed
PiperOrigin-RevId: 629159171

google/shopping/type/types.proto

@@ -22,13 +22,37 @@ option java_multiple_files = true;
 option java_outer_classname = "TypesProto";
 option java_package = "com.google.shopping.type";
 
+// The weight represented as the value in string and the unit.
+message Weight {
+  // The weight unit.
+  enum WeightUnit {
+    // unit unspecified
+    WEIGHT_UNIT_UNSPECIFIED = 0;
+
+    // lb unit.
+    POUND = 1;
+
+    // kg unit.
+    KILOGRAM = 2;
+  }
+
+  // Required. The weight represented as a number in micros (1 million micros is
+  // an equivalent to one's currency standard unit, for example, 1 kg = 1000000
+  // micros).
+  // This field can also be set as infinity by setting to -1.
+  // This field only support -1 and positive value.
+  optional int64 amount_micros = 1;
+
+  // Required. The weight unit.
+  // Acceptable values are: kg and lb
+  WeightUnit unit = 2;
+}
+
 // The price represented as a number and currency.
 message Price {
   // The price represented as a number in micros (1 million micros is an
   // equivalent to one's currency standard unit, for example, 1 USD = 1000000
   // micros).
-  // This field can also be set as infinity by setting to -1.
-  // This field only support -1 and positive value.
   optional int64 amount_micros = 1;
 
   // The currency of the price using three-letter acronyms according to [ISO