Android场景 - 002 - 返回/Home按钮【即Actionbar/Toolbar最左侧按钮】图标设置

1 相关类与方法：
-ActionBarDrawerToggle
setDrawerIndicatorEnabled
syncState
onConfigurationChanged
onOptionsItemSelected
setHomeAsUpIndicator
onDrawerOpened
onDrawerClosed
onDrawerSlide
onDrawerStateChanged
-ActionBar
setDisplayHomeAsUpEnabled
setHomeActionContentDescription
setDisplayOptions
-DrawerLayout
setDrawerListener
setDrawerShadow
closeDrawers
isDrawerOpen
setDrawerLockMode
-Toolbar
setNavigationIcon
setNavigationOnClickListener
setTitle