Update git submodules

* Update platform/external/libevent from branch 'master'
  to d2693d5cef76b2ada1f0abeff2a3ecfd93ddbdc3
  - Clear apex.go entries for bluetooth libs
    
    The module availability to Bluetooth is currently hard-coded in apex.go.
    We are in the process of cleaning the apex.go by adding the availability
    in each required module
    
    Test: Build + TH + boot phone & use bluetooth
    Bug: 216433795
    Change-Id: I209b24a68da8c21f9eddb2518e57667b0d9bab79
    
  - Empty merge of sc-v2-dev-plus-aosp-without-vendor@8084891
    
    Bug: 214455710
    Merged-In: I8c47d3d11c15125010aa4771be0abf205fd22ef6
    Change-Id: Ie5f878449ea2dc15fd57c1e58f17519a8075c227
    
  - Adding min_sdk_version to libevent required for bt apex am: 8dd4c4c4dc
    
    Original change: https://android-review.googlesource.com/c/platform/external/libevent/+/1932217
    
    Change-Id: Id8edb9c3b40a5cc2ac83b36f18ce19f3a7e826d5
    
  - Fix external/libevent compiling against musl am: b6bd404f19 am: a413947f3a am: 14a590a4e5 am: e05af653ec
    
    Original change: https://android-review.googlesource.com/c/platform/external/libevent/+/1826832
    
    Change-Id: Idd2c9749ed4c61cd625274a1ef6b04ab6cb88b23
    
  - [automerger skipped] Revert "Add ramdisk_available to init_first_stage's deps" am: f4db89ce07 am: f3b58a6f53 -s ours
    
    am skip reason: Merged-In I044a075b7f8faf75e3ff8ef25ae01afc2aac5a32 with SHA-1 03001bd1cf is already in history. Merged-In was found from reverted change.
    
    Reverted change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15067035
    
    Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15167750
    
    Change-Id: I44dec1091eeb540b349df90141ad1202defead2b
    
  - [automerger skipped] Revert "Add ramdisk_available to init_first_stage's deps" am: f4db89ce07 -s ours am: 554553dddb -s ours
    
    am skip reason: Merged-In I044a075b7f8faf75e3ff8ef25ae01afc2aac5a32 with SHA-1 03001bd1cf is already in history. Merged-In was found from reverted change.
    
    Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15167750
    
    Change-Id: I340a87643a550f8912e21cf1cee4d21c49318430
    
  - Revert "Add ramdisk_available to init_first_stage's deps" am: f4db89ce07
    
    Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15167750
    
    Change-Id: Ie9bcc008f498cdac3fe3f7518cc1924cefe6e413
    
  - [automerger skipped] Add ramdisk_available to init_first_stage's deps am: 019e3d06ad am: b590067966 -s ours
    
    am skip reason: Merged-In I044a075b7f8faf75e3ff8ef25ae01afc2aac5a32 with SHA-1 019e3d06ad is already in history
    
    Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15067035
    
    Change-Id: If5efb993c739293f815798aa6a4db32ac37c93ff
    
  - [automerger skipped] Add ramdisk_available to init_first_stage's deps am: 019e3d06ad -s ours am: 54a8c028f8 -s ours
    
    am skip reason: Merged-In I044a075b7f8faf75e3ff8ef25ae01afc2aac5a32 with SHA-1 03001bd1cf is already in history
    
    Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15067035
    
    Change-Id: Ice44549fe01b9d352c011ec3055367bf656cbe76
    
  - Add ramdisk_available to init_first_stage's deps am: 019e3d06ad
    
    Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libevent/+/15067035
    
    Change-Id: Icb063de2fdc71140eac5d41e5848e217d4c32cb6
    
  - Add ramdisk_available to init_first_stage's deps am: 03001bd1cf am: 99e17c9b83 am: 9c03bbca68
    
    Original change: https://android-review.googlesource.com/c/platform/external/libevent/+/1736435
    
    Change-Id: Idfad4a3040b72b3f8e144dc89fd92bb1a504387f