Android : Memory leak due to java.lang.ref.FinalizerReference in Android

I am developing an Android application. I have found a memory leak due to java.lang.ref.FinalizerReference in AudioManager in my application. But,i have not used audio manager in my project or libraries. What could be the issue and how to fix the memory leak

Class Name                                                                                                                    | Shallow Heap | Retained Heap
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mOuterContext android.app.ContextImpl @ 0x422d7e90                                                                            |          120 |           696
|- context android.app.ActivityThread$ContextCleanupInfo @ 0x41fef240 Unreachable                                             |           24 |           160
|- mContext android.media.AudioManager @ 0x4235f650                                                                           |           48 |           160
|  '- this$0 android.media.AudioManager$1 @ 0x4235f750                                                                        |           24 |            24
|     '- referent java.lang.ref.FinalizerReference @ 0x4235f770                                                               |           40 |        37,896
|        '- next java.lang.ref.FinalizerReference @ 0x4235f7b0                                                                |           40 |        37,936
|           '- next java.lang.ref.FinalizerReference @ 0x4235ff20                                                             |           40 |        37,976
|              '- next java.lang.ref.FinalizerReference @ 0x4235ff90                                                          |           40 |        38,016
|                 '- next java.lang.ref.FinalizerReference @ 0x42360918                                                       |           40 |        38,056
|                    '- next java.lang.ref.FinalizerReference @ 0x42360d90                                                    |           40 |        38,096
|                       '- next java.lang.ref.FinalizerReference @ 0x42365a60                                                 |           40 |        38,136
|                          '- next java.lang.ref.FinalizerReference @ 0x42365ec0                                              |           40 |        38,176
|                             '- next java.lang.ref.FinalizerReference @ 0x42398c40                                           |           40 |        38,216
|                                '- next java.lang.ref.FinalizerReference @ 0x42398cc0                                        |           40 |        38,256
|                                   '- next java.lang.ref.FinalizerReference @ 0x42373710                                     |           40 |        38,296
|                                      '- next java.lang.ref.FinalizerReference @ 0x42373eb0                                  |           40 |        38,336
|                                         '- next java.lang.ref.FinalizerReference @ 0x42374310                               |           40 |        38,376
|                                            '- next java.lang.ref.FinalizerReference @ 0x422b63d0                            |           40 |        38,416
|                                               '- next java.lang.ref.FinalizerReference @ 0x42381ce0                         |           40 |        38,456
|                                                  '- next java.lang.ref.FinalizerReference @ 0x423e22d0                      |           40 |        38,496
|                                                     '- head class java.lang.ref.FinalizerReference @ 0x417100d0 System Class|           16 |        38,608
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