Add "Available since" text to all android/ headers.

Also fix a few missing/incorrect annotations.

Bug: http://b/143470841
Test: treehugger
Change-Id: I1d9ec8350df03df7d80f1cc2334eef45deec30ec
diff --git a/include/android/font.h b/include/android/font.h
index 8001ee1..1618096 100644
--- a/include/android/font.h
+++ b/include/android/font.h
@@ -96,6 +96,8 @@
 /**
  * Close an AFont.
  *
+ * Available since API level 29.
+ *
  * \param font a font returned by ASystemFontIterator_next or AFontMatchert_match.
  *        Do nothing if NULL is passed.
  */
@@ -116,6 +118,8 @@
  * The font file returned is guaranteed to be opend with O_RDONLY.
  * Note that the returned pointer is valid until AFont_close() is called for the given font.
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \return a string of the font file path.
  */
@@ -184,6 +188,8 @@
  *
  * For more information about font weight, read [OpenType usWeightClass](https://docs.microsoft.com/en-us/typography/opentype/spec/os2#usweightclass)
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \return a positive integer less than or equal to {@link ASYSTEM_FONT_MAX_WEIGHT} is returned.
  */
@@ -192,6 +198,8 @@
 /**
  * Return true if the current font is italic, otherwise returns false.
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \return true if italic, otherwise false.
  */
@@ -204,6 +212,8 @@
  *
  * Note that the returned pointer is valid until AFont_close() is called.
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \return a IETF BCP47 compliant language tag or nullptr if not available.
  */
@@ -216,6 +226,8 @@
  * returns a non-negative value as an font offset in the collection. This
  * always returns 0 if the target font file is a regular font.
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \return a font collection index.
  */
@@ -247,6 +259,8 @@
  *
  * For more information about font variation settings, read [Font Variations Table](https://docs.microsoft.com/en-us/typography/opentype/spec/fvar)
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \return a number of font variation settings.
  */
@@ -258,6 +272,8 @@
  *
  * See AFont_getAxisCount for more details.
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \param axisIndex an index to the font variation settings. Passing value larger than or
  *        equal to {@link AFont_getAxisCount} is not allowed.
@@ -271,6 +287,8 @@
  *
  * See AFont_getAxisCount for more details.
  *
+ * Available since API level 29.
+ *
  * \param font a font object. Passing NULL is not allowed.
  * \param axisIndex an index to the font variation settings. Passing value larger than or
  *         equal to {@link ASYstemFont_getAxisCount} is not allwed.